Fix issue tapping on some usernames

[micahmo]

Pull Request Description

This PR fixes an issue where we couldn't navigate to some user pages because they were federated users from different platforms. For example, there is @remindme@mstdn.social which is a valid Lemmy user, but mstdn.social is not a Lemmy instance.

Previously we would check if the instance name was a valid Lemmy instance, so I removed that check. Note that this is still safe (in case we encounter an invalid user) because we already had a try/catch around navigateToUserPage. If it fails, we will still fall back to classic web navigation.

This also speeds up the check, because isLemmyInstance would often attempt to make an API call to the instance.

It's unclear whether we should also remove this check from getLemmyCommunity, since I'm unsure whether communities can be federated from non-Lemmy instances.

Issue Being Fixed

Issue Number: N/A

Screenshots / Recordings

qemu-system-x86_64_aKCI14NBZf.mp4

Checklist

• Did you update CHANGELOG.md?
• Did you use localized strings where applicable?
• Did you add semanticLabels where applicable for accessibility?

[hjiangsu]

LGTM!