APIv4 post /channels/ids (#5845)

* APIv4 post /channels/ids

* updated enpoint as /teams/{team_id}/channels/ids

store/store.go

@@ -103,6 +103,7 @@ type ChannelStore interface {
 	GetChannels(teamId string, userId string) StoreChannel
 	GetMoreChannels(teamId string, userId string, offset int, limit int) StoreChannel
 	GetPublicChannelsForTeam(teamId string, offset int, limit int) StoreChannel
+	GetPublicChannelsByIdsForTeam(teamId string, channelIds []string) StoreChannel
 	GetChannelCounts(teamId string, userId string) StoreChannel
 	GetTeamChannels(teamId string) StoreChannel
 	GetAll(teamId string) StoreChannel