batch deletions on azure / limited to 256 - Closes #509

[alikefia]

One of the implementations of delete folder on azure lists all the blobs and delete them directly. The delete request on azure blobs is limited to 256 objects per request (https://learn.microsoft.com/en-us/python/api/azure-storage-blob/azure.storage.blob.containerclient?view=azure-python#azure-storage-blob-containerclient-delete-blobs)
The proposal is to batch the call

---

Contributor checklist:

• I have read and understood CONTRIBUTING.md
• Confirmed an issue exists for the PR, and the text Closes #issue appears in the PR summary (e.g., Closes #123).
• Confirmed PR is rebased onto the latest base
• Confirmed failure before change and success after change
• Any generic new functionality is replicated across cloud providers if necessary
• Tested manually against live server backend for at least one provider
• Added tests for any new functionality
• Linting passes locally
• Tests pass locally
• Updated HISTORY.md with the issue that is addressed and the PR you are submitting. If the top section is not `## UNRELEASED``, then you need to add a new section to the top of the document for your change.

[pjbull]

Thanks @alikefia, looks good in principal. Can you follow the other checklist items to lint, add changelog entry, and add a test?

[alikefia]

Test running on master branch (fixed fail)

[pjbull]

@alikefia Looks like batched isn't available in all the versions of Python we support. We can add a backport with the implementation from the docs: https://docs.python.org/3/library/itertools.html#itertools.batched

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 92.3%. Comparing base (d3522c7) to head (f7e2dc4).
Report is 1 commits behind head on 508-live-tests.

Additional details and impacted files

@@               Coverage Diff                @@
##           508-live-tests    #508     +/-   ##
================================================
- Coverage            93.7%   92.3%   -1.4%     
================================================
  Files                  23      23             
  Lines                1798    1800      +2     
================================================
- Hits                 1685    1663     -22     
- Misses                113     137     +24     

Files with missing lines	Coverage Δ
cloudpathlib/azure/azblobclient.py	84.8% <100.0%> (-9.5%)	⬇️

... and 2 files with indirect coverage changes

🚀 New features to boost your workflow:

• ❄ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[pjbull]

Docs failure is unrelated; pushing to local branch to run live tests.