MM-49564: Drafts upsert in the Store vs App layer (#22530)

* MM-49564: Upsert in the Store vs App layer

Refactor drafts so that Upserting a draft would happen in the DB and not
in the app layer.

* Fixes mocks

* Fixes tests

* Fixes translations

* Fixes tests

* Update tests

* Fixes tests

* Addresses review comments

- renames Save => Upsert
- removes Sleep from tests

* Fixes flaky test

---------

Co-authored-by: Mattermost Build <build@mattermost.com>

model/draft.go

@@ -81,9 +81,11 @@ func (o *Draft) GetProps() StringInterface {
 func (o *Draft) PreSave() {
 	if o.CreateAt == 0 {
 		o.CreateAt = GetMillis()
+		o.UpdateAt = o.CreateAt
+	} else {
+		o.UpdateAt = GetMillis()
 	}
 
-	o.UpdateAt = o.CreateAt
 	o.DeleteAt = 0
 	o.PreCommit()
 }
@@ -100,8 +102,3 @@ func (o *Draft) PreCommit() {
 	// There's a rare bug where the client sends up duplicate FileIds so protect against that
 	o.FileIds = RemoveDuplicateStrings(o.FileIds)
 }
-
-func (o *Draft) PreUpdate() {
-	o.UpdateAt = GetMillis()
-	o.PreCommit()
-}