*: website_form

Part of https://github.com/odoo/odoo/pull/55959
task-2157252

*: website

Commit [1] broke the UI for some options related to CSS variables when
using Chrome. The commit made sure the string-value CSS variables are
printed with quotes, so that the JS representation of the CSS values can
distinguish them (strings = strings with surrounding quotes, others like
colors, numbers, etc = strings without surrounding quotes). With chrome,
the printed surrounding single quotes are read as double quotes for
strange reasons though... so the value "a" was not considered equal to
the value 'a'.

This commit makes sure surrounding quotes are normalized. This is done
through a new utility function to read CSS variables. This also makes
sure the values are trimmed, and colors normalized.

[1]: https://github.com/odoo/odoo/commit/3a34e39caa8544059dfb1888edc29c62c3efde31

closes odoo/odoo#54757

Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>

*: web_editor

Some of those "⌙" markers will become foldable options in the future.

Part of https://github.com/odoo/odoo/pull/53930
task-2157252

closes odoo/odoo#53930

Related: odoo/upgrade#1478
Related: odoo/design-themes#332
Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>

*: mass_mailing, website_blog, website_forum, website_hr_recruitment

Deprecate alpha, beta, gamma, delta and espilon color names and now use
a new color system: o-color-x, with x from 1 to 5.

This will allow to review the colors of all themes to have nice visuals
for the new color combinations classes, without breaking the current
uses of bg-alpha, alert-delta, etc in current websites of customers
(by keeping the old color and classes for compatibility).

This will also allow to uniformize all themes under the same conventions
to enforce BS color override:
- o-color-1 used as primary (as before, for alpha)
- o-color-2 used as secondary (as before, for beta)

Before, some themes were not following the 2 guidelines. The users
using those themes will simply have the possibility to choose o-color-1
and o-color-2 colors accordingly to restore their website without
breaking the new system features.

Another change is that those colors are defined through color palettes
and not theme color palettes. This will avoid them to generate automatic
bootstrap classes which we don't want (alert, btn) and generate the one
we want by ourself.

Note: for mass mailing, the colors and classes also have been renamed
but the system stays unchanged.

Part of https://github.com/odoo/odoo/pull/45856
task-2197038

*: website, web

Move the colorpicker dialog logic into a colorpicker *widget*, which the
colorpicker dialog will now instantiate.

Part of https://github.com/odoo/odoo/pull/46088
task-2195313