[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/timerlayer/timerlayer.go

@@ -3059,6 +3059,22 @@ func (s *TimerLayerDraftStore) Delete(userID string, channelID string, rootID st
 	return err
 }
 
+func (s *TimerLayerDraftStore) DeleteEmptyDraftsByCreateAtAndUserId(createAt int64, userId string) error {
+	start := time.Now()
+
+	err := s.DraftStore.DeleteEmptyDraftsByCreateAtAndUserId(createAt, userId)
+
+	elapsed := float64(time.Since(start)) / float64(time.Second)
+	if s.Root.Metrics != nil {
+		success := "false"
+		if err == nil {
+			success = "true"
+		}
+		s.Root.Metrics.ObserveStoreMethodDuration("DraftStore.DeleteEmptyDraftsByCreateAtAndUserId", success, elapsed)
+	}
+	return err
+}
+
 func (s *TimerLayerDraftStore) Get(userID string, channelID string, rootID string, includeDeleted bool) (*model.Draft, error) {
 	start := time.Now()
 
@@ -3091,6 +3107,22 @@ func (s *TimerLayerDraftStore) GetDraftsForUser(userID string, teamID string) ([
 	return result, err
 }
 
+func (s *TimerLayerDraftStore) GetLastCreateAtAndUserIdValuesForEmptyDraftsMigration(createAt int64, userId string) (int64, string, error) {
+	start := time.Now()
+
+	result, resultVar1, err := s.DraftStore.GetLastCreateAtAndUserIdValuesForEmptyDraftsMigration(createAt, userId)
+
+	elapsed := float64(time.Since(start)) / float64(time.Second)
+	if s.Root.Metrics != nil {
+		success := "false"
+		if err == nil {
+			success = "true"
+		}
+		s.Root.Metrics.ObserveStoreMethodDuration("DraftStore.GetLastCreateAtAndUserIdValuesForEmptyDraftsMigration", success, elapsed)
+	}
+	return result, resultVar1, err
+}
+
 func (s *TimerLayerDraftStore) Upsert(d *model.Draft) (*model.Draft, error) {
 	start := time.Now()