Indicator of (simple) sliding sync API endpoint

### Your use case

#### What would you like to do?
Check which API my Client use.

#### Why would you like to do it?
I am not sure, what EXA is using:
- sliding sync proxy
- Synapse simple sliding sync

#### How would you like to achieve it?
Show additional state Informationen of user protocoll (simple or not) or maybe the url in the UI

### Have you considered any alternatives?

_No response_

### Additional context

What is the feature of sliding sync or simple sliding sync.
Should i prepare to switch oft / teardown my sliding sync proxy?

### Are you willing to provide a PR?

No