Introduce stdlib types and methods for dealing with raw bytes

[lsh]

Review Mojo's priorities

• [X] I have read the roadmap and priorities and I believe this request falls within the priorities.

What is your request?

At minimum it would be useful to have a data structure like

struct Bytes:
  var data: DynamicVector[UInt8]

Naming is a bikeshed issue.

What is your motivation for this change?

Since the String type will have a small string optimization, there needs to be a way to convert a string to the expected ByteArray representation. Therefore we'd need .to_bytes on String.

Any other details?

It's worth considering how this type fits in with the generic std list type. It should also probably fit in with the Base64 module.

[drunkwcodes]

.to_bytes is not pythonic. Do you mean str.encode(encoding='utf-8', errors='strict')?

[gabrieldemarmiesse]

I just noticed this issue, linking https://github.com/modularml/mojo/pull/2096 for better visibility