Add a loader over the editor if an option takes some time to be applied
to indicate that something is being done.
In this commit, the following changes have been made:
- Add "_execWithLoadingEffect" method (will be used to add actions
to the mutex queue and set a loading screen over the editor 1s later).
- As soon as the mutex is unlocked (all computations are completed),
the loading effect will be removed (or canceled).
Part of https://github.com/odoo/odoo/pull/55614
task-2213114
X-original-commit: a4a745cf4f9ccade9876d885ab0774d3ec0bbf69