When deleting a message for me, the image url wasn't preserved,
resulting in the image disappearing on the client side.
This commit adds the processing of returned messages so that the image
is preserved.
When we reply to our own message with an image, we didn't set the URL of
the image of the message, which resulted in the image not being
displayed correctly.
* fix(mentions): deleting or editing a mention should remove the mention
* test(edit): add a test for mentions in edits
* test(delete): add test for deleting a message with a mention
* fix(image-album): make sure to delete all images part of an album
* test(delete): add test that deletes a message part of an album
* test(delete): add test where the signal to delete images is after
also adds the handling of deleteForMe
* fix(delete): add album deletion handling for deleteForMe