[MM-62427] Add message attachments validation (#30180)

* Add message attachments validation

* Add props validation

* Validate slack attachment fields

* Update tests and library usage

* Improve interactive dialog error for length checks

* Allow predefined colors for slack attachments

* Fix TestPostAction

* Use const for data source

* Add tests

* Cleanup unused props

* Add happy path tests

* lint fixes

* Add validation for PostActionOptions

server/channels/store/timerlayer/timerlayer.go

@@ -6433,10 +6433,10 @@ func (s *TimerLayerPostStore) Overwrite(rctx request.CTX, post *model.Post) (*mo
 	return result, err
 }
 
-func (s *TimerLayerPostStore) OverwriteMultiple(posts []*model.Post) ([]*model.Post, int, error) {
+func (s *TimerLayerPostStore) OverwriteMultiple(rctx request.CTX, posts []*model.Post) ([]*model.Post, int, error) {
 	start := time.Now()
 
-	result, resultVar1, err := s.PostStore.OverwriteMultiple(posts)
+	result, resultVar1, err := s.PostStore.OverwriteMultiple(rctx, posts)
 
 	elapsed := float64(time.Since(start)) / float64(time.Second)
 	if s.Root.Metrics != nil {
@@ -6561,10 +6561,10 @@ func (s *TimerLayerPostStore) Save(rctx request.CTX, post *model.Post) (*model.P
 	return result, err
 }
 
-func (s *TimerLayerPostStore) SaveMultiple(posts []*model.Post) ([]*model.Post, int, error) {
+func (s *TimerLayerPostStore) SaveMultiple(rctx request.CTX, posts []*model.Post) ([]*model.Post, int, error) {
 	start := time.Now()
 
-	result, resultVar1, err := s.PostStore.SaveMultiple(posts)
+	result, resultVar1, err := s.PostStore.SaveMultiple(rctx, posts)
 
 	elapsed := float64(time.Since(start)) / float64(time.Second)
 	if s.Root.Metrics != nil {