Track in app events server side

### Epic

_No response_

### Description

**As a:** Product Manager

**I want to:** Capture events from _all_ users, not just users without ad-blocking

**So that:** I have a better picture of use the usage patterns of FlowForge

In https://github.com/flowforge/flowforge/pull/1922 PostHog tracking was expanded client side to capture various actions a user might take at the client side API level.

However, this won't capture any events from users with an ad-blocker in their browser as the tracking is handled entirely client side.

Moving event tracking server side should be considered to reduce the size of the blind spot.

A good start would be to add `identify` server side, and see if user numbers increase, to give an idea of the percentage of events that are currently being missed.

### Which customers would this be availble to

Other (See comments)

### Acceptance Criteria

- [ ] Larger number of users tracked in post hog
- [ ] Event tracking works even if user blocks post hog in browser