[REF] web_editor: prevent concurrency issue in resetEditor

The PR #105579 introduce the call of `setupCollaboration` in
`resetEditor` but did not remove the instructions in `resetEditor`
that will be called in `setupCollaboration`.

`this._getNewPtp` should be called by `setupCollaboration` as it is
called after an asynchronous call.

Additionally, `this._peerToPeerLoading` has to be awaited to prevent
concurrency issues.

closes odoo/odoo#110150

Signed-off-by: David Monjoie (dmo) <dmo@odoo.com>