Refactor post page quick actions

[hjiangsu]

Pull Request Description

This PR refactors the post page quick actions bar into its own widget PostQuickActionsBar. This is mainly to simplify the PostSubview widget and will pave the way for the post page refactor!

This will also make #1197 a bit easier to implement!

Issue Being Fixed

Issue Number: N/A

Screenshots / Recordings

Checklist

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

[micahmo]

Makes sense and LGTM!

Would this also be a good opportunity to fix the padding so that the divider above the quick actions can be full width? I think that will require removing the overall padding and then adding it back to the individual elements except the divider.

[hjiangsu]

Would this also be a good opportunity to fix the padding so that the divider above the quick actions can be full width?

This can be done at a later step! I'm slowly working on refactoring parts of the post view in chunks (see #1281 for more refactoring logic)