Improve categories dropdown blur behavior

Latest changes to the parent issue may cover this. Clicking outside the category dropdown, or tabbing off it, will cause the drop-down to close.

If someone could just verify / test and include a screencast or something, we could close this probably then.

as @lostcarpark outlined. with the latest version of 2.0.x-dev the modal collapses on tab, on esc and on clicking outside the modal as demonstrated in close.mp4

IChecked this in version 2.0.x-dev and can confirm as mentioned by @rkoller that the filter by category dropdown is getting closed on click of esc, tab and outside click. Added video for reference.