[services] Tests - Blob - Add Remove

Summary:
Depends on D4275

Adding Remove method to blob's tests.

Test Plan: For now, this method's not invoked. The Rust project should build normally.

Reviewers: palys-swm, varun

Reviewed By: palys-swm, varun

Subscribers: ashoat, palys-swm, Adrian, atul, yayabosh

Differential Revision: https://phab.comm.dev/D4276