feat: created functions to get multiple signed URLs.

[dishwad]

Addresses issues:
#104

[anand2312]

LGTM

[anand2312]

@dishwad run poetry run pre-commit install locally to install pre-commit hooks so that black is automatically run on every commit - that's what seems to be failing in CI right now 😄

Also you don't have to manually write the code for the sync client, we generate that using unasync - poetry run unasync storage3 and poetry run unasync tests generates sync code for us 😅 I should probably document that somewhere

[dishwad]

Ok I removed the code for the sync client and the sync test. I ran poetry run pre-commit install locally and black is passing for me locally.

[J0]

Hm might be the case that poetry version of black doesn't tally with the pre commit hook config. Former is 23.3.0 and latter is 23.1.0. Let me bump - might need to trouble you to rerun

[anand2312]

Odd - the pre-commit hook for black was reformatting tests/_async/test_client.py on CI but ignoring it locally. Running black manually on that file seems to have fixed it.
Thanks for the PR @dishwad!