Add API Endpoint for deleted Channels (#5889)

store/store.go

@@ -103,6 +103,7 @@ type ChannelStore interface {
 	GetByName(team_id string, name string, allowFromCache bool) StoreChannel
 	GetByNameIncludeDeleted(team_id string, name string, allowFromCache bool) StoreChannel
 	GetDeletedByName(team_id string, name string) StoreChannel
+	GetDeleted(team_id string, offset int, limit int) StoreChannel
 	GetChannels(teamId string, userId string) StoreChannel
 	GetMoreChannels(teamId string, userId string, offset int, limit int) StoreChannel
 	GetPublicChannelsForTeam(teamId string, offset int, limit int) StoreChannel