Improved new posts view with avatar of the posters

[PrajeetShrestha]

Added a expandable pending notification indicator with avatars of the accounts who posted the status.

Note:

• Code to scroll to last pending status is not altered in this pull request, and does not seem to be at working state as of now.
• There are two new strings added: expanded and shrinked. I have added it to english string resource Localizable(english) only.

[PrajeetShrestha]

Looks like there were some changes in codebase. I will reopen after verifying my changes works as expected.

[PrajeetShrestha]

Tried different approaches to achieve this but I think unpublished status in "PendingStatusesObserver" would be more cleaner approach to do it.

[Dimillian]

Closing it for now, I like the idea but I'll rework it into something a bit different when I'll have time.