Add a mechanism to buffer external steps when some asynchronous rendering needs
to be done (i.e. OWL rendering). This is to prevent external steps occuring
inside the rendered result from being applied when the rendering is currently
ongoing.
Remove `historyResetFromSteps` and `onExternalHistorySteps` as they were only
introduced to trigger an update of Knowledge Behaviors, but now that update is
done through `checkForExtraRendering`.
Modify collaborative tests of the editor so that steps `afterCreate` and
`afterCursorInserted` can be asynchronous.
Task-2821374
Part-of: odoo/odoo#104680