MM-21552: Adding SaveMultiple to posts (#13766)

* Adding SaveMultiple to posts

* Improving tests

* fixing i18n

* Fixing tests

* Improving testing on top of Save and SaveMultiple

* Fixing shadow variables

* Addressing some PR comments

* More clear update post test

* Addressing some PR comments

* Addressing some PR comments and simplifying the code

* Improting replies in bulk too

* Fixing reply count and processing last imported replies

* Adding OverwriteMultiple to posts aggregating everything in the same transaction

* Adding 2 pending tests to implement

* Adding tests for overwrite multiple posts

* Adding tests for TeamStore.GetByNames method

* Fixing shadow variables

* Addressing PR comments

* Extracting i18n strings

* Fixing tests

* Fixing tests

* Adding more test cases

* Using a variable instead of a fake timestamp

store/timer_layer.go

@@ -4412,6 +4412,22 @@ func (s *TimerLayerPostStore) Save(post *model.Post) (*model.Post, *model.AppErr
 	return resultVar0, resultVar1
 }
 
+func (s *TimerLayerPostStore) SaveMultiple(posts []*model.Post) ([]*model.Post, *model.AppError) {
+	start := timemodule.Now()
+
+	resultVar0, resultVar1 := s.PostStore.SaveMultiple(posts)
+
+	elapsed := float64(timemodule.Since(start)) / float64(timemodule.Second)
+	if s.Root.Metrics != nil {
+		success := "false"
+		if resultVar1 == nil {
+			success = "true"
+		}
+		s.Root.Metrics.ObserveStoreMethodDuration("PostStore.SaveMultiple", success, elapsed)
+	}
+	return resultVar0, resultVar1
+}
+
 func (s *TimerLayerPostStore) Search(teamId string, userId string, params *model.SearchParams) (*model.PostList, *model.AppError) {
 	start := timemodule.Now()