[stdlib] Add __refitem__ to List

[JoeLoser]

As the TODO suggests, rename __get_ref to be __refitem__. Then, we can remove List.__getitem__. This will require fixing up a bunch of callers that previously were using List.__getitem__ to now dereferenced the returned Reference from List.__refitem__, e.g. my_list[some_index][].

[StandinKP]

I can take this up @JoeLoser

[JoeLoser]

I can take this up @JoeLoser

I appreciate the enthusiasm, but unfortunately this one may be blocked on #2441 as @mikowals started taking a look at this I think.

[JoeLoser]

Blocked by #2441

[StandinKP]

No problem. LMK if I should take up anything on priority or I can browse through some of the older issues and pick sth up @JoeLoser

[JoeLoser]

No problem. LMK if I should take up anything on priority or I can browse through some of the older issues and pick sth up @JoeLoser

Will certainly do! I'm planning on adding several GitHub issues to the public repo this week, so stay tuned 😄

[StandinKP]

Perfect🔥

[JoeLoser]

Removed blocked label since it appears to have been a user error. See my comment at #2441 (comment).