This allows generic subcommands to be passed to reckless-rpc along with
the target to search/install/etc.. These commands are unvalidated so
far and may crash the reckless process.
Changelog-Added: reckless-rpc plugin: issue commands to reckless over rpc.
Any file in this directory which is executable and whose name only
consists of alphanumeric characters, space, '.', '-' or '_' will be
automatically loaded when lightningd starts (unless suppressed with
commandline options).