Prior to it being compulsory, these daemons would need a default value. Now it's
always required, it's clearer if it's always told.
There's no "default_channel_type" now everyone has to specify channel_type either,
so rename it to "desired_channel_type" and put it in lightningd specifically.
Note that the channel_type can have options added: either option_scid_alias or option_zeroconf.
This results in a slight behavior change: we will get type zeroconf even if we didn't ask for it, if they gave it to us.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Changelog-Changed: JSON-RPC: fundchannel / fundchannel_start returned `channel_type` will include option_zeroconf if it was implied by a 0 minimum_depth, even if we didn't explicitly ask for a zero conf channel.
506fa914e0