style: add make changelog_style for automatic changelog formatting

[romanz]

Added also to make style.

[no changelog]

[github-actions]

core UI changes	device test	click test	persistence test
T2T1 Model T	test(screens) main(screens)	test(screens) main(screens)	test(screens) main(screens)
T3B1 Safe 3	test(screens) main(screens)	test(screens) main(screens)	test(screens) main(screens)
T3T1 Safe 5	test(screens) main(screens)	test(screens) main(screens)	test(screens) main(screens)
All	main(screens)

[matejcik]

this is becoming rather fragile, instead embed this list into generate-changelog
and make it fail if someone tries to use a non-listed path, telling them to also add the thing they want to the known path list

(that way we have a single command for "changelog check" and "changelog style" and we enforce that every changelog used by someone will be added to that list)

[romanz]

Sounds good, thanks for the suggestion!
WDYT about 0132526?

[romanz]

(I've also added @mmilata, since he is the author of tools/generate-changelog.py)

[mmilata]

Looking good, but also please update references to generate-changelog.py in docs/misc/changelog.md.

[romanz]

Looking good, but also please update references to generate-changelog.py in docs/misc/changelog.md.

Thanks!
Updated in dcb3b2a.

[romanz]

Squashed and rebased over main.