Implement greet inbox and outbox

- Add user_greet model and startup table sync
- Implement /greet/user and /greet/delete handlers
- Implement noticeFriendGreeting inbox and noticeUserGreetingHistory outbox
- Return peer profile and center unit info for greeting notices
- Update login topInfo friend greet counters from unread inbox messages

Signed-off-by: Sean Du <do4suki@gmail.com>

internal/startup/database.go

@@ -28,6 +28,7 @@ func CreateTables() {
 	db.UserEng.Sync2(new(usermodel.UserLiveInProgress))
 	db.UserEng.Sync2(new(usermodel.UserLiveRecord))
 	db.UserEng.Sync2(new(usermodel.UserFriend))
+	db.UserEng.Sync2(new(usermodel.UserGreet))
 	db.UserEng.Sync2(new(usermodel.UserPref))
 	db.UserEng.Sync2(new(usermodel.Users))
 	db.UserEng.Sync2(new(usermodel.UserUnit))