[REF] web: backport .text-bg-#{$color} from BS 5.2

Add the new helper `.text-bg-#{$color}` to restore the old behaviour like in
BS4 for the `.bg-#{$color}`

In short, in BS5 `.bg-#{$color}` don't change anymore the text color but
only the background. `.text-bg-#{$color}` change both color text and
background.

Task ID: 2766483

Part-of: odoo/odoo#95450

addons/web/__manifest__.py

@@ -327,6 +327,7 @@ This module provides the core of the Odoo Web Client.
         ],
         'web._assets_bootstrap': [
             'web/static/src/legacy/scss/import_bootstrap.scss',
+            'web/static/src/libs/bootstrap/helpers_backport.scss',
             'web/static/src/legacy/scss/bootstrap_review.scss',
         ],
         'web._assets_backend_helpers': [

addons/web/static/src/libs/bootstrap/helpers_backport.scss

@@ -0,0 +1,14 @@
+// Backport from BS 5.2
+// TODO remove me when migrate to new Bootstrap 5.2 +
+
+$prefix: '' !default;
+$theme-colors: () !default;
+
+// All-caps `RGBA()` function used because of this Sass bug: https://github.com/sass/node-sass/issues/2251
+@each $color, $value in $theme-colors {
+    $color-rgb: to-rgb($value);
+    .text-bg-#{$color} {
+        color: color-contrast($value) !important;
+        background-color: RGBA($color-rgb, var(--#{$prefix}bg-opacity, 1)) !important;
+    }
+}