Abbrevated DM recipient names in message feeds, Drafts and Scheduled
messages overlays by wrapping recipient names in span with class
private_message_header_name and applying `overflow: hidden` and
`text-overflow: ellipsis` CSS to it.
Fixes#25353
Fixes#25340
This means that we now schedule the message simply after selecting
time if the message is valid.
Also, editing scheduled messages will now delete the scheduled
message and open compose with scheduled message.
This commit removes the keyboard shortcut from tooltips that
can be seen when hovering over the two buttons in
"View Scheduled Messages" modal.
This is a temporary change as the keyboard shortcut will be
added to the tooltips when the shortcuts are actually working.