[MM-53428] Delete empty drafts on upsert (#24046)

* [MM-53428] Delete empty drafts on upsert

* Add migrations to fix existing drafts

* Fix CI

* Delete empty drafts entirely from the DB

* Fix lint

* Implement batch migration for deleting drafts

* Missing store layers

* Add updated mock

* Remove unnecessary test

* PR feedback

* Add check for cluster migration

* Fix MySQL

* Don't check for len<2

* Bit of PR feedback

* Use query builder for parameters

* PR feedback

* More PR feedback

* Merge'd

* unit test GetLastCreateAtAndUserIdValuesForEmptyDraftsMigration

* simplified builder interface

* fix DeleteEmptyDraftsByCreateAtAndUserId for MySQL

* rework as batch migration worker

* fix typo

* log ip address on version mismatches too

* simplify reset semantics

* remove trace log in favour of low spam

* document parameters for clarity

---------

Co-authored-by: Mattermost Build <build@mattermost.com>
Co-authored-by: Jesse Hallam <jesse.hallam@gmail.com>

server/channels/store/store.go

@@ -986,6 +986,8 @@ type DraftStore interface {
 	Get(userID, channelID, rootID string, includeDeleted bool) (*model.Draft, error)
 	Delete(userID, channelID, rootID string) error
 	GetDraftsForUser(userID, teamID string) ([]*model.Draft, error)
+	GetLastCreateAtAndUserIdValuesForEmptyDraftsMigration(createAt int64, userId string) (int64, string, error)
+	DeleteEmptyDraftsByCreateAtAndUserId(createAt int64, userId string) error
 }
 
 type PostAcknowledgementStore interface {