Shorten and rationalize command names.

[evoskuil]

Rename

fetch-compact-filter-checkpoint-node
fetch-compact-filter-headers-node
fetch-compact-filters-node
match-neutrino-filter-address
match-neutrino-filter-script
send-tx-node
send-tx-p2p

to

get-filter-checkpoint
get-filter-headers
get-filters
match-neutrino-address
match-neutrino-script
put-tx
broadcast-tx

'fetch'/'send' imply libbitcoin server
'get'/'put' imply single p2p node
'broadcast' implies p2p network (multiple nodes)
'neutrino' implies neutrino compact filters
'filter' implies compact filter

Renames to put-tx and broadcast-tx will require compatibility shims.

[pmienk]

If you haven't started I can take this. Am currently expanding server and client to support filter queries, I think the -node should stay to distinguish.