- focus will always enter the tagsBox popup opened from the reader
- escape from within the popup with tagsBox will close the popup (vpat
67)
- one should not be able to collapse the tagsBox. Added `collapsible`
getter and setters to the collapsible panel to prevent the section
from changing its open status. This may be also used in other cases,
such as to prevent itemBox from being collapsed in duplicates mode.
- patched a glitch where tab from the last empty tab input would loose
focus.
- changed the `menupopup` for `panel` to display the `tagsbox` because
`menupopup` has implicit `role="menu"` which is not meant to contain
inputs, so voiceover completely looses cursor when inputs are focused
inside of the popup. Also, tweaked spacing a bit to avoid the
focus-ring getting cutoff.
Addresses: #4222Fixes: #4230Fixes: #4226
Addresses: #4388
