This *would* be a 1-line change (add it to Makefile) except that we
previously assumed a "list" prefix on commands.
These use the default refreshing, but they could be done better using
the time-range parameters.
Suggested-by: @niftynei
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
In particular, we generate the schema part from the plugin itself.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Changelog-Added: Plugins: `sql` plugin command to perform server-side complex queries.
