[IMP] web_editor, *: add new user value colorpicker widget

* web, mass_mailing, website

Introduced a new sub-widget for snippet options: we-colorpicker. This
allows to retrieve a color value (either a normalized css color or a
theme color name) to be used for a snippet option method.

This commit replaces the old 'colorpicker' snippet option whose behavior
is now simply achieved by defining an xml option using a we-colorpicker
widget in combination with the 'selectStyle' standard method.

This commit also adds the possibility to control the border-color of
elements alongside their border-width. Again, just a we-colorpicker
widget in combination with the 'selectStyle' standard method.

Note: this commit reviewed what the colorpalette palette widget
notifies. This is not a cssColor and a 'isClass' flag to say if it is
a css class or not. The colorpalette always returns a color string which
can be the name of a color like 'alpha'. This is up to the caller to
check if the color string is a css color or not with isCSSColor. In the
case it is not, the related code can read the actual color by reading
the related css variable.

Part of https://github.com/odoo/odoo/pull/40282
In preparation of task-2122935 and other tasks

1 files changed, 6 insertions, 0 deletions

diff --git a/addons/web_editor/static/src/scss/web_editor.common.scss b/addons/web_editor/static/src/scss/web_editor.common.scss
index baac51c3adf..2de7d389843 100644
--- a/addons/web_editor/static/src/scss/web_editor.common.scss
+++ b/addons/web_editor/static/src/scss/web_editor.common.scss
@@ -2,6 +2,12 @@
 /// This file regroups basic style rules for web_editor enable page edition and backend utils.
 ///
 
+:root {
+    @each $color, $value in $grays {
+        --#{$color}: #{$value};
+    }
+}
+
 html, body {
     position: relative;
     width: 100%;