faa26d3744 test: Remove RPCOverloadWrapper boilerplate (MarcoFalke)
Pull request description:
There are too many wrappers in test_node already, so at least the code that implements the wrappers should be as minimal as possible.
ACKs for top commit:
laanwj:
code review ACK faa26d3744
Tree-SHA512: 94e593907de22187524e2445afb3101e40b3b599d4b4015aa8c6ca902d7586ff9daf520828759029d199a3af79e61b96b490a822a5a193ac7bf946beacb11a24