This commit removes "button" and "rounded" class from the button and
add the required rules to the pre existing sticky-bottom-option class.
Fixes part of #35006.
Adds `sticky_bottom_option` element to the `dropdown_widget` to
support moving of "Add a new saved snippet" button to the bottom
sticky area of the dropdown for better accessibility and UX.
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.
This commit adds filter_text_input class to various search inputs
used across the app. This new class is used to re-add the bootstrap
CSS rules such that we can remove the CSS from bootstrap.css.
