User Block Behaviour Improvement

I further improved the way we handle user blocks. This doesn't change the underlying blocking behaviour on the platform, but it reinforces that user blocks follow symmetric content visibility. Other features remain unchanged; neither user will see any content from the other while a block is in place. If one user blocks another user, both users will: - be able to load the profile (but only a profile shell with no information loads) - not see any content, pictures, or online activity Cheers!