[REF] *: make stronger bootstrap assets

* portal, theme_bootswatch, web, web_editor, website

With less2sass and bs3tobs4 tasks, the assets structure was reviewed to
handle the specificities of both framework and to prepare for our next
odoo tasks. In particular, the assets_helpers and bootstrap overrides
were basically split into 4 parts: utils, primary variables, secondary
variables and bootstrap variables.
(see https://github.com/odoo/odoo/commit/6e4db7d13a926845bf82f5b035afede42d6d5a89)

Using the !default system for the bootstrap variables parts seems now
a good improvement. This is part of what this commit does: adding the
default flag for all bootstrap variables overrides and inverting the
order of the files in the _assets_backend_helpers and
_assets_frontend_helpers templates. This allows to avoid code like this:

portal:
```
$body-bg: white;
```

website:
```
@​if $var != null {
    $body-bg: $var;
}
```

This code makes the body white with portal or equal to $var with website
if $var has a value. The same behavior in the new file order is achieved
with:

website:
```
$body-bg: $var !default;
```

portal:
```
$body-bg: white !default;
```

This order is now also followed for the _assets_secondary_variables
templates (there are only a few).

This commit also make better assets hierarchy by making website inherit
from portal assets (instead of web) and portal inherit from web_editor
assets (instead of web) (thus relying on strong dependencies instead of
installation order which is not always right for migrated databases).

closes odoo/odoo#29757

2 files changed, 41 insertions, 20 deletions

diff --git a/addons/web_editor/static/src/scss/bootstrap_overridden.scss b/addons/web_editor/static/src/scss/bootstrap_overridden.scss
index 5c64d275d56..0bfc53c5091 100644
--- a/addons/web_editor/static/src/scss/bootstrap_overridden.scss
+++ b/addons/web_editor/static/src/scss/bootstrap_overridden.scss
@@ -2,29 +2,14 @@
 $-is-backend: variable-exists('primary');
 
 // Use auto threshold for yiq colors
-$yiq-contrasted-threshold: false;
+$yiq-contrasted-threshold: false !default;
 
 // Automatically update bootstrap colors map (unused by BS itself)
-$-palette: nth($o-color-palettes, $o-color-palette-number);
 $colors: () !default;
-$colors: map-merge($-palette, $colors);
+$colors: map-merge($o-color-palette, $colors);
 
 // Automatically extend bootstrap to create theme background/text/button classes
-$-palette: nth($o-theme-color-palettes, $o-theme-color-palette-number);
-$-main-color: map-get($-palette, 'alpha');
-$-main-color-lightness: lightness($-main-color);
-$-palette: map-merge((
-    // alpha and beta colors are used to override primary and secondary BS4
-    // colors by default, so that theme colors affect the default Odoo layouts
-    'primary': $-main-color,
-    'secondary': map-get($-palette, 'beta'),
-
-    // BS light and dark colors are not used for any BS component, just
-    // for color utilities. By default, we set them to a very light and
-    // very dark version of a desaturate version of the main color
-    'light': lighten(desaturate($-main-color, 80%), min(70%, max(0%, 97% - $-main-color-lightness))), // Does not increase over 97% lightness
-    'dark': darken(desaturate($-main-color, 80%), min(70%, max(0%, $-main-color-lightness - 10%))), // Does not lower under 10% lightness
-), o-map-omit($-palette));
+$-palette: $o-theme-color-palette;
 @if $-is-backend {
     $-palette: map-remove($-palette, 'primary', 'secondary', 'success', 'info', 'warning', 'danger', 'light', 'dark');
 }
@@ -34,8 +19,7 @@ $theme-colors: map-merge($-palette, $theme-colors);
 // Extend grays with transparent ones (for some reason, BS4 create black-50 and
 // white-50 but does not allow overridding that with variables), also use the
 // theme gray palette (which is supposed to at least declare white and black).
-$-palette: nth($o-gray-color-palettes, $o-gray-color-palette-number);
-$-palette: map-merge($o-transparent-grays, $-palette);
+$-palette: $o-gray-color-palette;
 @if $-is-backend {
     $-palette: map-remove($-palette, '100', '200', '300', '400', '500', '600', '700', '800', '900');
 }
diff --git a/addons/web_editor/static/src/scss/secondary_variables.scss b/addons/web_editor/static/src/scss/secondary_variables.scss
new file mode 100644
index 00000000000..e1e4e62ca66
--- /dev/null
+++ b/addons/web_editor/static/src/scss/secondary_variables.scss
@@ -0,0 +1,37 @@
+
+//------------------------------------------------------------------------------
+// Colors
+//------------------------------------------------------------------------------
+
+// Colors
+$o-color-palette: nth($o-color-palettes, $o-color-palette-number) !default;
+@function palette-color($key) {
+    @return map-get($o-color-palette, $key);
+}
+
+// Theme colors
+$o-theme-color-palette: nth($o-theme-color-palettes, $o-theme-color-palette-number) !default;
+$-main-color: map-get($o-theme-color-palette, 'alpha');
+$-main-color-lightness: lightness($-main-color);
+$o-theme-color-palette: map-merge((
+    // alpha and beta colors are used to override primary and secondary BS4
+    // colors by default, so that theme colors affect the default Odoo layouts
+    'primary': $-main-color,
+    'secondary': map-get($o-theme-color-palette, 'beta'),
+
+    // BS light and dark colors are not used for any BS component, just
+    // for color utilities. By default, we set them to a very light and
+    // very dark version of a desaturate version of the main color
+    'light': lighten(desaturate($-main-color, 80%), min(70%, max(0%, 97% - $-main-color-lightness))), // Does not increase over 97% lightness
+    'dark': darken(desaturate($-main-color, 80%), min(70%, max(0%, $-main-color-lightness - 10%))), // Does not lower under 10% lightness
+), o-map-omit($o-theme-color-palette));
+@function palette-theme-color($key) {
+    @return map-get($o-theme-color-palette, $key);
+}
+
+// Gray colors
+$o-gray-color-palette: nth($o-gray-color-palettes, $o-gray-color-palette-number) !default;
+$o-gray-color-palette: map-merge($o-transparent-grays, $o-gray-color-palette);
+@function palette-gray($key) {
+    @return map-get($o-gray-color-palette, $key);
+}