Convert pedal and pedalboard images from .png to .webp to use less storage

[Rossmallow]

After noticing Issue #1856, I tried converting the pedal images to webp to reduce their size. I recently did a similar conversion from jpeg to webp for my own website and saved quite a bit of space.
As shown in the screenshots of my reply to that issue, using webp images instead of png reduced the size of the app/images/pedals directory from over 5GB to just over 500MB. A dramatic difference with no noticable drop in quality.

This is a huge PR with many files touched. Obviously it'll take some time to review and properly test, although I did manage to start up a local server and it seems to function just the same.
This will also "conflicts" with existing PRs as those images will be added as pngs.
Maybe a more strategic (and easier to review) approach to the conversion would be to convert one or two brands of pedals at a time. The code supports using both png and webp files simultaniously so a slower roll-out is possible.

ps. This branch also includes changes from my PR #2173 as they were already in my forked master branch.

[ArislanShiva]

I think this kind of wholesale change should be left up to @tehtrav, if he even feels it's necessary.

As contributors we should just stick to pedals and minor QOL improvements.

[Rossmallow]

Agreed.
I just wanted to make this branch as a proof-of-concept that, if implemented, could save a lot of money on hosting fees.
@tehtrav can certainly close this PR if it's unnecessary, but I do think it should be considered.