Improve performance of speaker.create and user.create

[r-peschke]

In a mail from @m-schieder from 23.08.2023 "Beobachtungen ... 2023-08-23" he wrote:

Allgemein konnten wir auch beobachten das die Backend Actions
"speaker.create" und "user.create" häufig in eine "action
worker" laufen.

Questions:
speaker.create: Could you see, whether there are especially point-of-orders affected?
user.create: Could you see, whether the action data contains the is_present_in_meeting_ids-field in special on slow cases?

[m-schieder]

speaker.create:
On my test system the server response takes about 500ms.
A point-of-orders with a speech list of 20 users about 900ms.