[native] Add drawer item implementations

Summary:
Linear issue: https://linear.app/comm/issue/ENG-1881/community-navigation-drawer-on-native
Add drawer item implementations. There are two types of drawer items - [community] and [a thread in a community]. They behave almost the same, but there is a difference when their expand buttons are toggled: only one community can be open, so opening a community sometimes has to trigger closing another. On the other hand multiple level 1 and level 2 threads can be open at once.
The information about which community is open is thus held by a parent component, and a community is passed an expanded flag and a setExpanded function allowing it to change its parents state.
On the other hand each thread keeps the information about being opened or not in their own state. Why?: They could be passed that information from a parent component, just like community, but then each community (and level 1 chat) would have to keep an array of these states for all its children. The renderItem method would then have to be dependent on this array, so if any child changed its 'open' state, the array would change, and in result all children would rerender.
This is why I created CommunityDrawerItemCommunity and CommunityDrawerItemChat components - to handle opening and closing elements according to the specification and avoid performance issues.

The CommunityDrawerItemChat is not in it's own file, because then I was receiving warnings (with stack traces) about a require cycle between files, since CommunityDrawerItemChat renders CommunityDrawerItem, and CommunityDrawerItem
has children that are CommunityDrawerItemChats. I'm not sure if I should put it in a separate file despite that. It seems like a bad idea, but having two components in one file like this seems unsanitary.

Test Plan: Tested with subsequent diffs.

Reviewers: tomek, atul, kamil, ginsu

Reviewed By: tomek

Subscribers: ashoat

Differential Revision: https://phab.comm.dev/D5721