replace aes-js library with webcrypto

[k-yle]

this was originally suggested on the osm discord, but it turns out that person is working on RapiD, not iD. so this PR backports the idea.

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like #11634, this reduces the bundle size by about 0.1MB.

AES-CTR is natively supported by WebCrypto, and support by all browsers since 2020.

So the question is: do we need to support 6-year-old browsers?

• we already use modern browser features with no error handling..., which means iD already crashes in 5-year-old browsers
• our browserslist config means that we only support 2-year-old browsers, with a few expections.

[bhousel]

Probably worth doing, but part of why I hesitated switching this out in Rapid was because it switches the decryption from sync to async. It's still probably a good idea, but I didn't want to audit all the places that the code is used.

[k-yle]

thanks bryan, yeah it was it bit cumbersome to make it fit into the synchronous code, but thankfully it's only used in those 2 places

[tyrasd]

yeah, that should be fine. btw: osm-auth also relies on webcrypto being available.

[tyrasd]

@k-yle: would you like to add this to the changelog as well?

[k-yle]

sure, done