Begin of the insertion**As** an openproject developer
**I** want a complete timelines API
**so that** timelines data can be queried distinguishedly.

**Acceptance criteria**

- The API v2 allows to query Users in a way similar toEnd of the insertion Begin of the deletion Currently,End of the deletion the Begin of the insertionother models
- The query can be limited to only a set of users identified by ids toEnd of the insertion Begin of the deletion APIv2 doesEnd of the deletion not Begin of the insertionslow timeline loading down
- The timelines UI uses that information to display assignees and responsiblesEnd of the insertion Begin of the deletion support users.End of the deletion