This will allow users to use clnrest with c-lightning-REST without conflicts.
It was required for applications to have enough time for migrating from c-lightning-REST to clnrest.
Changelog-Changed:
config option `rest-certs` changed to `clnrest-certs`
config option `rest-protocol` changed to `clnrest-protocol`
config option `rest-host` changed to `clnrest-host`
config option `rest-port` changed to `clnrest-port`
config option `rest-cors-origins` changed to `clnrest-cors-origins`
config option `rest-csp` changed to `clnrest-csp`
