Pinned Posts Enhancements and Fixes

[lammylol]

A general bucket of items to finish up Pinned Posts in the Today Feed and Profile. Fixed a bunch of issues with Pinned Posts currently, and also provided some enhancements such as an 'empty post' overlay if uses don't have any pinned posts. Users can now more easily pin a post when they create or edit a post as well.

Call out: Refresh correctly works, but not an automatic load after submitting a post (can consider in the future depending on API query costs)

What to Test:

• If there are more than 2 'pinned posts', users should be able to click the 'show all' button, which should expand all the posts
• Users should be able to select 'pin a post' when either 1) creating a new post, or 2) editing an existing post
• Navigation: Users should be able to click into each post card and navigate back and forth between the main screen.
• Notification: Friends of a user should see a notification alert when an existing prayer they follow is updated.

[lammylol]

'What to test' listed above. I'm excited for this PR to go to main. Once basic comments are ready (with or without notifications), I think we have a very tangible item to release to TestFlight.