Add a License Filter

[jrconway3]

I think this would be a huge benefit:

Add a license filter similar to the "Animations" filter. Now that I finally posted a release for the Expanded ULPC, as well as a second one for heads and head parts:
https://opengameart.org/content/expanded-universal-lpc-spritesheet-idle-run-jump-lpc-revised-combat-and-assets
https://opengameart.org/content/expanded-ulpc-all-heads-body-partsextensions

I realized just how annoying it is not being able to see which assets belong to which license unless I first check the credits. I'd like to be able to simply grab assets utilizing a specific license.

What I propose is having a License filter where we can list off all the OGA licenses and have each sheet filled with those licenses. Then you can filter by just one license, whatever it is you wish. For me for example I mostly prefer working with OGA-BY. It also could be an easy way for me to see where certain assets are missing.

This obviously would take a ridiculously long time to add in everything, so I'd just slowly add them over time.

[sanderfrenken]

Hmm that sounds handy to have indeed. We should be able to programmatically achieve this.

For instance, we could use the credits.csv while we generate the html to add specific attributes which we can use to filter in JS. I think that could work. I can spend some time on it in the coming days.

Alternatively, it would be nice to add it to the sheet_definitions directly. But that is very hard as the attribution can be different even within an asset: for instance, the muscular body shirt variant might have been created by Pete, while the same shirt male's variant was created by Pete and Dave, and the female variant is created by Elisa. I think this might even be the case for some recolors as well.

[jrconway3]

Oh crap, I forgot about that. I was planning to just drop it into sheet_definitions, but I forgot that different versions are sometimes made by different people and have different licenses. Yeah if you can figure it out using the credits.csv that's probably the better bet, and more convenient--we wouldn't need to add it to every sheet in that case.

[sanderfrenken]

I created a PR with preliminary work for this topic, would like to hear your thoughts!

#223