currently, after a user edits a message and removes an reference to the
uploaded file, the uploaded file stays on the storage taking up space.
We want to ask the user to possibly delete the removed attachments if
they are no longer needed. These changes applies a modal that will appear
prompting the user to delete the attachments.
Fixes: #25525.
Co-authored-by: brijsiyag
Co-authored-by: wandrew0
joseph