[FIX] web_editor: inlines should be pasted inside container

During paste HTML, an inline element or a textNode should never be
inserted outside of the targeted initial container.

Those kind of orphans elements should never be present in an HTML paste data,
but better safe than sorry.

Part-of: odoo/odoo#95347

# Conflicts:
#	addons/web_editor/static/lib/odoo-editor/src/OdooEditor.js

Part-of: odoo/odoo#95445

addons/web_editor/static/src/js/editor/odoo-editor/src/OdooEditor.js

@@ -55,6 +55,7 @@ import {
     getAdjacentPreviousSiblings,
     getAdjacentNextSiblings,
     rightLeafOnlyNotBlockPath,
+    isBlock,
 } from './utils/utils.js';
 import { editorCommands } from './commands/commands.js';
 import { Powerbox } from './powerbox/Powerbox.js';
@@ -2198,7 +2199,31 @@ export class OdooEditor extends EventTarget {
         for (const child of [...container.childNodes]) {
             this._cleanForPaste(child);
         }
-        return container.innerHTML;
+        // Force inline nodes at the root of the container into separate P
+        // elements. This is a tradeoff to ensure some features that rely on
+        // nodes having a parent (e.g. convert to list, title, etc.) can work
+        // properly on such nodes without having to actually handle that
+        // particular case in all of those functions. In fact, this case cannot
+        // happen on a new document created using this editor, but will happen
+        // instantly when editing a document that was created from Etherpad.
+        const temporaryContainer = document.createElement('template');
+        let temporaryP = document.createElement('p');
+        for (const child of [...container.childNodes]) {
+            if (isBlock(child)) {
+                if (temporaryP.childNodes.length > 0) {
+                    temporaryContainer.content.appendChild(temporaryP);
+                    temporaryP = document.createElement('p');
+                }
+                temporaryContainer.content.appendChild(child);
+            } else {
+                temporaryP.appendChild(child);
+            }
+
+            if (temporaryP.childNodes.length > 0) {
+                temporaryContainer.content.appendChild(temporaryP);
+            }
+        }
+        return temporaryContainer.innerHTML;
     }
     /**
      * Clean a node for safely pasting. Cleaning an element involves unwrapping