[Fix] Added key accessibility for most LFD features

[YaroslavOvdii]

@sofiiakvasnevska

Issue

https://github.com/Fliplet/fliplet-studio/issues/6423

Description

Added key accessibility for most LFD features

Screenshots/screencasts

https://share.getcloudapp.com/KourrkeE

Backward compatibility

This change is fully backward compatible.

Reviewers

@upplabs-alex-levchenko

Notes

Created new PR for this PR to avoid conflicts with others PRs.

[tonytlwu]

Conflicts to resolve

[tonytlwu]

https://share.getcloudapp.com/KourrkeE

1. The first 6 seconds of the video tabs from Menu > Search bar > Bookmarks > Filters. The outline highlights all look slightly different. They need to look consistent in its opacity, fade, thickness etc.
2. At around 0:08, when the filters are activated, the focus should stay on the Filter toggle so that users can press ENTER repeatedly to toggle the filters on and off.
3. At 0:34, the disabled date selectors should not be TAB-able because they don't do anything.
4. At 1:17, it looks like you had to click on the overlay a few times. Why was that? Is it because you pressed TAB a few times and nothing happened? Is it because it was cycling through the elements behind the overlay?
5. At 3:11, it looks like it took you a while to focus on the comment field. Did you have to press TAB multiple times? The overlay opening should allow users to start TAB-ing through the overlay UI elements right away

[tonytlwu]

This looks like the main the list being toggled on and off. Why?

And when the list is shown again, does it restore its scroll position? e.g. if the list was previously scrolled to 30% down the list, does it restore to the same point?