[REF] web, *: BS4, use custom BS4 checkbox everywhere

Before this commit, Odoo used checkboxes in three different ways:

- A simple <input type="checkbox"/>, mainly in the frontend. The style
  is browser dependant.

- Same as above but with the BS3, checkbox structure. The style is still
  the same, but the alignement is supposed to be better (which is not
  always the case).

- The Odoo official structure:
	```
	<div class="o_checkbox">
	    <input type="checkbox"/>
	    <span/>
	</div>
	```
  which allows to have a cross-browser checkbox style and correct
  alignements.

The goal after this commit is to only use the BS4 *custom* checkbox
structure to achieve the same goal as our official structure (and
remove that one):

```
<div class="custom-control custom-checkbox">
  <input type="checkbox" class="custom-control-input" id="customCheck1">
  <label class="custom-control-label" for="customCheck1">...</label>
</div>
```

/!\ Labels are now required (use a zero-width space if necessary)

1 files changed, 2 insertions, 2 deletions

diff --git a/addons/web/static/src/js/fields/relational_fields.js b/addons/web/static/src/js/fields/relational_fields.js
index 73bcc1f1f35..ba83de415e7 100644
--- a/addons/web/static/src/js/fields/relational_fields.js
+++ b/addons/web/static/src/js/fields/relational_fields.js
@@ -1887,7 +1887,7 @@ var FormFieldMany2ManyTags = FieldMany2ManyTags.extend({
             this.$color_picker.dropdown('toggle');
             this.$color_picker.attr("tabindex", 1).focus();
             if (!tagColor) {
-                this.$('.o_checkbox input').prop('checked', true);
+                this.$('.custom-checkbox input').prop('checked', true);
             }
         }
     },
@@ -1909,7 +1909,7 @@ var FormFieldMany2ManyTags = FieldMany2ManyTags.extend({
         var changes = {};
 
         if ($target.is('.o_hide_in_kanban')) {
-            var $checkbox = $('.o_hide_in_kanban .o_checkbox input');
+            var $checkbox = $('.o_hide_in_kanban .custom-checkbox input');
             $checkbox.prop('checked', !$checkbox.prop('checked')); // toggle checkbox
             this.prevColors = this.prevColors ? this.prevColors : {};
             if ($checkbox.is(':checked')) {