* PLT-5677 Make System messages mark channels as unread equals to the webapp
* addressing feedback
* Clarify when the channel should be mark as read
* ignored posts types dont change the channel read state
* fix typo
* Fix placement of new messages separator
* Ignore your own posts when determining start of new messages
* Cache lastViewedAt in ChannelPostList until switching channels
* Increase padding around DateHeader & NewMessagesDivider
* Improve styling of new messages divider line
* Use async await for ChannelDrawerList.onSelectChannel
* Convert DateHeader to functional component
* Indicate start of new messages in posts list
* Use flag prop to indicate start of new messages in posts list
* Declare style props with View.propTypes.style
* Added selectChannel action
* Fixed selected team not being cleared on logout
* Fixed posts and postsByChannel not being initialized correctly
* Added basic post rendering
* Renamed selectors files to be plural
* Removed empty file
* Fixed unit tests after merge
* Removing unnecessary code