chanacceptor+lnrpc: update the commitmentTypes, send zero-conf to client

This updates the RPCAcceptor to send the correct commitment type
even if the zero-conf or scid-alias channel types are set. This also
adds two bools to the ChannelAcceptRequest struct that denotes whether
the funder set the zero-conf and scid-alias channel types.

lnrpc/lightning.proto

@@ -926,6 +926,14 @@ message ChannelAcceptRequest {
 
     // The commitment type the initiator wishes to use for the proposed channel.
     CommitmentType commitment_type = 14;
+
+    // Whether the initiator wants to open a zero-conf channel via the channel
+    // type.
+    bool wants_zero_conf = 15;
+
+    // Whether the initiator wants to use the scid-alias channel type. This is
+    // separate from the feature bit.
+    bool wants_scid_alias = 16;
 }
 
 message ChannelAcceptResponse {