Allow searching for a tag and bulk-adding games to a competition

[dfabulich]

When creating a competition (e.g. IFComp 2022), someone has to add each game to IFDB (this is hard work in its own right!), then click "Create a Competition" and add each game to the competition's page.

But, in addition, each game in a given competition gets a tag, e.g. the "IFComp 2022" tag.

It would be a lot easier if the "create a competition" or "edit a competition" page would allow users to search for a tag, and then bulk-add all of the games that match that tag to the competition as entrants.

[dfabulich]

But, when the competition closes, somebody still has to manually enter in all of the results, 1st place, 2nd place, etc. Maybe we just have to assume that in order for the competitions pages to work, good samaritans are going to do a ton of manual labor.

[dfabulich]

I'm most of the way there. You can copy-and-paste this script into your JS Console to add all games with a certain tag to the main division. https://github.com/iftechfoundation/ifdb/blob/main/ifcomp-importer/entrant-creator.js

I'd just need to add a button to the competition UI, but I think that would require me to convert some of the existing image-based buttons into non-images so I could add a new button.