This takes part of the work being done in #96 that was reverted but still useful.
Note Tailwind and Fresh weren't upgraded because there's no security vulnerability in either, and I have found the new versions to be worse in performance. Thos will likely stay at those fixed versions going forward.
This implements the option to choose directories when uploading files via the Web UI (The most important part of #52).
When you choose a directory, its file and sub-directory structure will be maintained.
Tested with the latest Safari, Firefox, and Chrome.
Additionally, the Deno version was updated, which required some accessibility improvements as well.
