Speech bubble customization options

[SheepTester]

I think for now, there only needs to be an option for a custom background and text colour for say/think bubbles. In Scratch 3.0, ask bubbles are the same as say bubbles (no sensing colour outline)

De Discord (discrim 4800)

[SheepTester]

I reject because it is not in a repo essential for custom aspect ratio

https://github.com/LLK/scratch-render/blob/4ebea93adf72d7c93cef1d4640a3b7c240f89177/src/TextBubbleSkin.js#L21-L24

However, perhaps the HTMLifier could find the equivalent object in the minified VM output and replace accordingly

[SheepTester]

Might be nice to have a fork of scratch-render I guess

Also, now also requested by 721909562277625906