[IMP] web_editor, *: remove assets from documents

* web

"Document" tab in "Select a media" Dialog was displaying all the assets
files. Now all files containing "assets_" are excluded from the
"Document" tab. This is similar to the regenerateAssets function in
debug_manager that deletes assets based on this criteria.

For consistency the Assets Domain is now a utils.js function

Part of https://github.com/odoo/odoo/pull/33195
task-1945874

addons/web/static/src/js/core/utils.js

@@ -771,7 +771,18 @@ var utils = {
         }
         return curr;
     },
-
+    /**
+     * Returns the domain targeting assets files.
+     *
+     * @returns {Array} Domain of assets files
+     */
+    assetsDomain: function () {
+        return [
+            '&',
+            ['res_model', '=', 'ir.ui.view'],
+            ['name', 'like', 'assets_']
+        ];
+    },
 };
 
 return utils;

addons/web/static/src/js/tools/debug_manager.js

@@ -88,10 +88,7 @@ var DebugManager = Widget.extend({
      */
     regenerateAssets: function () {
         var self = this;
-        var domain = [
-            ['res_model', '=', 'ir.ui.view'],
-            ['name', 'like', 'assets_']
-        ];
+        var domain = utils.assetsDomain();
         this._rpc({
             model: 'ir.attachment',
             method: 'search',

addons/web_editor/static/src/js/wysiwyg/widgets/media.js

@@ -821,6 +821,14 @@ var DocumentWidget = FileWidget.extend({
         this.$addUrlButton.text((isURL && isImage) ? _t("Add as image") : _t("Add document"));
         this.$urlWarning.toggleClass('d-none', !isURL || !isImage);
     },
+    /**
+     * @override
+     */
+    _getAttachmentsDomain: function (needle) {
+        var domain = this._super.apply(this, arguments);
+        // the assets should not be part of the documents
+        return domain.concat('!', utils.assetsDomain());
+    },
 });
 
 /**