build: Add meson build system

Reuse the generated dbus interface .xml files from fprintd to avoid
unnecessary copies.

tests/pam/services/meson.build

@@ -0,0 +1,13 @@
+# Meson doesn't allow to have configure_file's as targets we depend on... Meh!
+pam_service_file = custom_target('pam_test_service_file',
+    output: 'null',
+    command: 'true',
+    depends: pam_fprintd,
+    depend_files: configure_file(
+        input: 'fprintd-pam-test.in',
+        output: 'fprintd-pam-test',
+        configuration: configuration_data({
+            'FPRINTDPAMPATH': pam_fprintd.full_path(),
+        }),
+    ),
+)