Better error messages for when features are disabled on a users HS

### Your use case

#### What would you like to do?
have more descriptive errors on why something is not working, such as adding a phone number in element on matrix.org
#### Why would you like to do it?
to reduce the amount of people asking about why something isnt working with a cryptic error message
#### How would you like to achieve it?
have a way for the app to know if something is disabled on the HS and to share that to the user easily when they try to use such feature thats turned off

### Have you considered any alternatives?

_No response_

### Additional context

_No response_

### Are you willing to provide a PR?

No

The issue names no files, tests, or entry points. Start by identifying the Element client and the homeserver-disabled feature/error path involved, then clarify how the app should receive and present the reason; done means users see a descriptive explanation instead of a cryptic failure.

Written by the indexing model from the issue text.