1. When we receive a commando command from a remote using the `filter`
field, use it.
2. Add a `filter` parameter to `commando` to send it: this is usually
more efficient than using filtering locally.
Of course, older remote nodes will ignore the filter, but that's
harmless.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Changelog-Added: Plugins: `commando` now supports `filter` as a parameter (for send and receive).
Rusty Russell