[blob] Fix Clippy warnings in Blob service

Summary:
Similiar to D12175 - some warnings in Blob Service.
Mostly about "too large enum varinat" - it suggested boxing error and that's what I did

Depends on D12175

Test Plan: cargo build -p blob

Reviewers: varun

Reviewed By: varun

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D12176