Fix avatar not updating on profile image change

[dlukt]

This PR ensures that when a user updates their profile picture, the old avatar is properly removed from both memory and disk caches across the application.

It accomplishes this by:

1. Extending ImageCache.remove() to explicitly remove images from the diskCache.
2. Emitting a new AccountInfoUpdatedEvent from AccountSessionManager when account information is updated.
3. Subscribing to this new event in HomeFragment, ComposeFragment, ThreadFragment, and ProfileFragment to selectively clear the old avatar cache and reload the new image via ViewImageLoader.

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PR created automatically by Jules for task 11625104379478555274 started by @dlukt

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