Fixes#30403.
Having tabIndex set to 0 led to keyboard focus being put on
a scrollbar container, which led to users having to tab twice
to skip a container.
This commit also removes instances of tabIndex being set to
-1 programatically for certain cases, since it is -1 by default now.
This commit also removes `outline: none` for simplebar since
that property is not needed anymore because the wrapper is
not focusable anymore.
Earlier the `/poll` slash command was the only way to create polls.
To increase user friendliness with a GUI, a button to launch a modal
to create a poll, has been added to the compose box. This button is
enabled only when the compose box is empty, to avoid complexities with
losing / having to save as draft any message already being composed.
The modal has a form which on submission frames a message using the
`/poll` syntax and the data input in the form, and sets the content of
the compose box to that message, which the user can then send. The
question field is mandatory for form submission.
Fixes: #20304.
Karl Stolley
Shubham Padia
N-Shar-ma