FEAT: Join Server Preview

[Asraye]

Current issues;

• It doesn't like you trying to join servers you are already in, I couldn't seem to make it correctly skip and go to navigation for this.
• Joining a server will navigate you to the correct channel, but not switch the server sidebar to correctly fit

↑ I am unsure on how to fix these above issues, and so far, any more changes to try and fix them, breaks it further, I (will likely) continue to try and fix them, unless someone else wishes too.. which I wouldn't be opposed

Please make sure to check the following tasks before opening and submitting a PR

• I understand and have followed the contribution guide
• I have tested my changes locally and they are working as intended

[insertish]

I think it would be more sensible to just re-use the invite preview modal, would be more DRY and provide a consistent flow for server invites. (it shows the background, etc as well)

[Asraye]

I think it would be more sensible to just re-use the invite preview modal, would be more DRY and provide a consistent flow for server invites. (it shows the background, etc as well)

I've begun having a look at doing this, I'll update it once It's completed – current issue is making the invite modal accept group invites.