Add ability to go to prev/next parent for comment navigator

[hjiangsu]

Pull Request Description

This PR improves the comment navigator for the new post page. In particular, I've added long press actions which navigate to the prev/next top-level comment. I've also improved the logic for the navigator, and #1496 (comment) should be fixed!

Note: I wasn't sure if the desired action for the long press was to navigate to the prev/next parent, or the prev/next top-level comment. I've opted to do the latter since that makes more sense to me, but this can always be changed!

Issue Being Fixed

Issue Number: #1413

Screenshots / Recordings

Simulator.Screen.Recording.-.iPhone.15.Pro.Max.-.2024-10-21.at.15.21.36.mp4

Checklist

• If a new package was added, did you ensure it uses an appropriate license and is actively maintained?
• Did you use localized strings (and added appropriate descriptions) where applicable?
• Did you add semanticLabels where applicable for accessibility?

[micahmo]

The code LGTM!

In terms of the behavior, I would advocate for the short-press to navigate between top-level comments. I believe that's the most common action, especially considering top-level comments are often off-screen, so it's not as easy to scroll to them. I also checked a couple other apps.

• Relay for Reddit: Short-press navigates top-level comments
• Sync for Lemmy: Short-press navigates top-level comments; long-press goes to the very top or bottom of the comments
• Boost for Lemmy: Same as Sync
• And of course, the old post page in Thunder also navigated top-level comments with a short-press, and we didn't have a long-press action on the arrows.

If you like long-press, maybe it could be a setting?

[hjiangsu]

In terms of the behavior, I would advocate for the short-press to navigate between top-level comments. I believe that's the most common action, especially considering top-level comments are often off-screen, so it's not as easy to scroll to them. I also checked a couple other apps.

I think that's reasonable! I went ahead and made the changes you suggested in dbb94e5

[micahmo]

Nice, I think this is good to go!