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.swagger.json

@@ -3423,6 +3423,14 @@
         "commitment_type": {
           "$ref": "#/definitions/lnrpcCommitmentType",
           "description": "The commitment type the initiator wishes to use for the proposed channel."
+        },
+        "wants_zero_conf": {
+          "type": "boolean",
+          "description": "Whether the initiator wants to open a zero-conf channel via the channel\ntype."
+        },
+        "wants_scid_alias": {
+          "type": "boolean",
+          "description": "Whether the initiator wants to use the scid-alias channel type. This is\nseparate from the feature bit."
         }
       }
     },