[identity] Add function to remove holders for devices

Summary:
Created a blob submodule in Identity for blob service actions.
Created function that calls Blob remove-multiple-holders endpoint for all holders prefixed by given device IDs.
Used exponential backoff to retry eventual failed holders.

Depends on D13648, D13649, D13643

Test Plan: Took a test from D13648 test plan, moved to Identity and called the new function in place of the direct BlobServiceClient call

Reviewers: varun, will, kamil

Reviewed By: kamil

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D13650