Use DataTable for Name Selection

[anisfeld]

Describe Your Changes

Now we have a DataTable that allows the administrator

to filter using the search bar
to select participants by clicking on the names of players
to get client-side feedback on whether the selection works (6 players, 3 from a given language group)

I left the old form in the HTML for now -- this makes it easier to control the number of games that will be played and may come in handy in future iterations or be deleted.

Non-Obvious Technical Information

Checklist Before Requesting a Review

• The code runs successfully.

24-01-10 13:47:38 INFO:     172.18.0.1:58348 - "GET /admin/session HTTP/1.1" 200 OK
2024-01-10 13:47:46 INFO:     172.18.0.1:58338 - "POST /admin/session HTTP/1.1" 302 Found
2024-01-10 13:47:46 INFO:     172.18.0.1:58338 - "GET /admin/dashboard?success=Your+session+%28ID%3A+8%29+and+first+game+%28ID%3A+82%29+have+been+created%21 HTTP/1.1" 200 OK