Adding is_pinned attribute to post and direct_post objects when doing bulk import (#19487)

* refactor: added is_pinned attribute to post and direct_post objects when doing bulk import

* fix: handling IsPinned nil value in post and direct_post objects import

* refactor: added pinned post tests for post and direct_post objects import

* refactor: TestImportimportMultiplePostLines code enhancements + added pinned post tests in TestImportImportDirectPost

* fix: test message text

* fix: typo Post => DirectPost

* fix: typo Post => DirectPost

* refactor: remove redundant test

* refactor: test enhancements

* refactor: remove print statements.

* refactor: using require instead of assert

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

app/import_functions.go

@@ -1407,6 +1407,9 @@ func (a *App) importMultiplePostLines(c *request.Context, lines []LineImportWork
 		if line.Post.Props != nil {
 			post.Props = *line.Post.Props
 		}
+		if line.Post.IsPinned != nil {
+			post.IsPinned = *line.Post.IsPinned
+		}
 
 		fileIDs := a.uploadAttachments(c, line.Post.Attachments, post, team.Id)
 		for _, fileID := range post.FileIds {
@@ -1715,6 +1718,9 @@ func (a *App) importMultipleDirectPostLines(c *request.Context, lines []LineImpo
 		if line.DirectPost.Props != nil {
 			post.Props = *line.DirectPost.Props
 		}
+		if line.DirectPost.IsPinned != nil {
+			post.IsPinned = *line.DirectPost.IsPinned
+		}
 
 		fileIDs := a.uploadAttachments(c, line.DirectPost.Attachments, post, "noteam")
 		for _, fileID := range post.FileIds {