control: unit test for event sort

After some discussions with CLAUDE it made me this unit test, which
I think is ok and actually tests useful things.

spa/plugins/control/meson.build

@@ -8,3 +8,33 @@ controllib = shared_library('spa-control',
   dependencies : [ spa_dep, mathlib ],
   install : true,
   install_dir : spa_plugindir / 'control')
+
+test_inc = include_directories('../test')
+
+test_apps = [
+  'test-mixer-ump-sort',
+]
+
+foreach a : test_apps
+  test(a,
+    executable(a, a + '.c',
+      dependencies : [ spa_dep ],
+      include_directories : [ configinc, test_inc ],
+      install_rpath : spa_plugindir / 'control',
+      install : installed_tests_enabled,
+      install_dir : installed_tests_execdir / 'control'),
+      env : [
+        'SPA_PLUGIN_DIR=@0@'.format(spa_dep.get_variable('plugindir')),
+        ])
+
+    if installed_tests_enabled
+      test_conf = configuration_data()
+      test_conf.set('exec', installed_tests_execdir / 'control' / a)
+      configure_file(
+        input: installed_tests_template,
+        output: a + '.test',
+        install_dir: installed_tests_metadir / 'control',
+        configuration: test_conf
+        )
+  endif
+endforeach