Feature: Add object permissions grants

[hyperschwartz]

Description

This functionality was sorely missing from the application. It allows existing granters to grant access to objects to new values, instead of only on object write. It also adds a batch grant option that streams all added hashes as they are intercepted.

Change Summary

• Expose client dependencies as API to ensure downstream consumers don't need to hunt down and import their own versions.
• Add object and batch object grant optionality to the application server and client.
• Compile and export kotlin protos to allow for flow exposure in the client.
• Allow batch rpc processes to be configurable.
• Create new queries to facilitate granter access grant discovery.
• Expand the Gateway server tests to do round-trip calls into the ObjectService versus mocking it, ensuring that this new stuff actually works end-to-end.