Remove usages of Buffer so we don't need to ship the polyfill

[t3chguy]

For matrix-org/matrix-js-sdk#4569

Looks like we cannot get rid of Buffer entirely as https://www.npmjs.com/package/bloom-filters requires Buffers until Callidon/bloom-filters#70

[dbkr]

Nice, although why the clamped arrays?

[t3chguy]

Nice, although why the clamped arrays?

That's the signature coming out of rust crypto for QR codes, rather than having to convert on both sides it makes sense to just use the right type to begin with

The js-sdk was previously doing stuff like this and it just made no sense, I guess for intercompat with Node's Buffer which can be used interchangeably

Much cleaner to just deal with the right type in the first place

[dbkr]

Oh, fair enough - looks like it's probably the type that the wasm bindings pick by default I guess.