Allow customisation of the "Submit debug logs" modal

### Your use case

#### What would you like to do?

Want to customise:

- The text in the description
- The default values in the fields

#### Why would you like to do it?

Not every installation goes back to Element (the org), some element-web installations are configured with their own homeserver.

#### How would you like to achieve it?

These values should be replaceable in config.json.

### Have you considered any alternatives?

Rather than being set in config.json, maybe this should be set by the homeserver? Where is the rageshake server itself selected?

### Additional context

_No response_