[MM-45272] Fix MM-45272 (#24701)

* Fix MM-45272

* Properly handle permalinks

* Fix

* Fix tests

* Handle only not found case for team member

* Fix lint

* Use proper config value

* Separate permission in several statements

* Add tests

* Fix lint

* Revert changes on utils

* Address feedback and more fixes

* Address feedback

* Fix test

* Fix test and related bug

* Fix and reorder test

* Address feedback

* Address feedback

---------

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

server/channels/app/post_metadata_test.go

@@ -2820,7 +2820,7 @@ func TestSanitizePostMetadataForUserAndChannel(t *testing.T) {
 		require.Nil(t, appErr)
 
 		actual = th.App.sanitizePostMetadataForUserAndChannel(th.Context, post, previewedPost, directChannel, guest.Id)
-		assert.Nil(t, actual.Metadata.Embeds[0].Data)
+		assert.Len(t, actual.Metadata.Embeds, 0)
 	})
 
 	t.Run("should not preview for archived channels", func(t *testing.T) {
@@ -2882,7 +2882,7 @@ func TestSanitizePostMetadataForUserAndChannel(t *testing.T) {
 		})
 
 		actual = th.App.sanitizePostMetadataForUserAndChannel(th.Context, post, previewedPost, publicChannel, th.BasicUser.Id)
-		assert.Nil(t, actual.Metadata.Embeds[0].Data)
+		assert.Len(t, actual.Metadata.Embeds, 0)
 	})
 }