Add RPC Whitelist Feature from #12248

Summary:

• test: Add test for rpc_whitelist

This is a backport of Core PR12763

Test Plan:

ninja all check-all

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Subscribers: Fabien

Differential Revision: https://reviews.bitcoinabc.org/D5810