rpc: Assert that RPCArg names are equal to CRPCCommand ones (misc)

Summary:
This is a backport of core#19528 [4/4]
https://github.com/bitcoin/bitcoin/pull/19528/commits/fa77de2baa40ee828c850ef4068c76cc3619e87b

Depends on D10082

Test Plan: ninja all check-all

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D10083