Fixes bugs of when multiple messages are being edited simultaneously.
Specifically, typeahead is no longer broken, copying messages to clipboard
is less buggy, and resizing is no longer
broken when multiple messages are being edited.
* In most cases, eslint --fix with the right comma-dangle settings was
able to update the code correctly.
* The exceptions were cases where the parser incorrectly treated the
arguments to functions as lists/objects and added commas; these are
detectable with linters, and we fixed manually. Since this is test
code, we can be reasonably confident that just fixing the failures
suffices to correct any bugs introduced by making changes
automatically.
We originally waited for .message_edit_notice to appear, now we wait for
textarea.message_edit_content to disappear.
This is better because the previous code didn't correctly handle
editing the same message twice (the "EDITED" tag would still be there
from the first edit, so it wouldn't wait at all the second time!).
Cory Lynch
Igor Tokarev
Tim Abbott
Umair Khan
Rishi Gupta
Vishnu Ks