Investigate model store/single autoupdate

Follow up for #5829

Describe the bug
Issue is described in #5829. There seems to be an underlying issue that is fixed by a workaround in #5830.

How to Reproduce

1. Revert https://github.com/OpenSlides/openslides-client/pull/5830
2. Open Agenda item page
3. Create new poll
4. Min/Max amount of votes missing

Expected behavior
Fields should be visible.

Additional context
It seems like the meeting subscription from the single autoupdate request in agenda-forward-dialog.service.ts overwrites certain fields that are necessary for the poll form to work.
This could be caused by broken update handling in the clients model store.

Another observation was that the single request agenda_copy_meetings arrived together with the subscription topic_detail:subscription. This is expected but wrong. Single request should never be bundled with other subscriptions. The matching in the worker should be updated or naming restrictions for autoupdate requests should be enforced by the services apis (by for example automatically adding :single suffix to single requests + matching them accordingly).

NOTE THAT #5830 SHOULD NOT BE REVERTED WHEN FIXED

Reproduce the problem by reverting PR #5830, opening an agenda item, and creating a poll. Start with agenda-forward-dialog.service.ts and trace how the single autoupdate request and topic_detail:subscription are handled by the model store. Done means the poll's min/max vote fields remain visible and the single request is not bundled with other subscriptions; do not revert #5830.