Automatically track translation progress inside issue

[remmycat]

This change should get rid of the annoying task of always keeping the translation progress up to date.

The translation-progress.md will no longer be checked in, but the PR pipeline still runs the check-translation-jsons:no-write script to make sure we don't have any issues in the translation files. (The script no longer errors if the existing file doesn't exist / is different)

Instead, a new GitHub Action will update this issue: #1104 , which we can pin and possibly lock

I also tried to create a better overview table 🙂 and used a little React/HTML where the markdown would've gotten silly otherwise (reverted)

See remmycat#1 for an example of the output

[remmycat]

One thing I want to investigate before merging this is if it's really necessary to go for an html table here.

In previous tries I had put the <details> elements directly into the table cells, which turned out to be an awful idea. But there markdown tables were definitely not enough.

Now that it's really just the emoji and text in each cell, I think getting the HTML (and usage of React for rendering) out of this again might be much neater 🤔

[remmycat]

Done, back to markdown everything, output is much nicer to look at again.

[Sendouc]

Yup this looks fantastic :)