PLT-4167 Team Sidebar (#4569)

* PLT-4167 Team Sidebar

* Address feedback from PM

* change route from my_members to members

* bug fixes

* Updating styles for teams sidebar (#4681)

* Added PM changes

* Fix corner cases

* Addressing feedback

* use two different endpoints

* Bug fixes

* Rename model and client functions, using preferences to store last team and channel viewed

* Fix mobile notification count and closing the team sidebar

* unit test, fixed bad merge and retrieve from cached when available

* bug fixes

* use id for last channel in preferences, query optimization

* Updating multi team css (#4830)

api/post.go

@@ -824,6 +824,7 @@ func sendNotifications(c *Context, post *model.Post, team *model.Team, channel *
 	message.Add("post", post.ToJson())
 	message.Add("channel_type", channel.Type)
 	message.Add("channel_display_name", channel.DisplayName)
+	message.Add("channel_name", channel.Name)
 	message.Add("sender_name", senderUsername)
 	message.Add("team_id", team.Id)