meson: add transfer related files

meson.build

@@ -48,6 +48,10 @@ mconnect_src = [
 	'src/mconnect/property-proxy.vala',
 	'src/mconnect/share.vala',
 	'src/mconnect/io-job.vala',
+	'src/mconnect/transfer-manager.vala',
+	'src/mconnect/transfer-manager-proxy.vala',
+	'src/mconnect/transfer-interface.vala',
+	'src/mconnect/transfer-proxy.vala',
 	'src/mconnect/transfer-download.vala',
 	'src/mconnect/logging.vala',
 	'src/crypt/certificate.vala',