PLT-5483 Fix bug where flagged posts endpoint returned posts on other teams (#5765)

* Fix bug where flagged posts endpoint returned posts on other teams

* Include flagged posts from DMs/GMs

store/store.go

@@ -148,6 +148,7 @@ type PostStore interface {
 	PermanentDeleteByChannel(channelId string) StoreChannel
 	GetPosts(channelId string, offset int, limit int, allowFromCache bool) StoreChannel
 	GetFlaggedPosts(userId string, offset int, limit int) StoreChannel
+	GetFlaggedPostsForTeam(userId, teamId string, offset int, limit int) StoreChannel
 	GetPostsBefore(channelId string, postId string, numPosts int, offset int) StoreChannel
 	GetPostsAfter(channelId string, postId string, numPosts int, offset int) StoreChannel
 	GetPostsSince(channelId string, time int64, allowFromCache bool) StoreChannel