Add Adw.MessageDialog responses extension

tests/samples/responses.blp

@@ -0,0 +1,10 @@
+using Gtk 4.0;
+using Adw 1;
+
+Adw.MessageDialog {
+  responses [
+    cancel: _("Cancel"),
+    discard: _("Discard") destructive,
+    save: "Save" suggested disabled,
+  ]
+}

tests/samples/responses.ui

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<interface>
+  <requires lib="gtk" version="4.0"/>
+  <object class="AdwMessageDialog">
+    <responses>
+      <response id="cancel" translatable="true">Cancel</response>
+      <response id="discard" translatable="true" appearance="destructive">Discard</response>
+      <response id="save" enabled="false" appearance="suggested">Save</response>
+    </responses>
+  </object>
+</interface>

tests/test_samples.py

@@ -143,6 +143,17 @@ class TestSamples(unittest.TestCase):
             raise AssertionError()
 
     def test_samples(self):
+        try:
+            import gi
+
+            gi.require_version("Adw", "1")
+            from gi.repository import Adw
+
+            have_adw = True
+            Adw.init()
+        except:
+            have_adw = False
+
         self.assert_sample("accessibility")
         self.assert_sample("action_widgets")
         self.assert_sample("child_type")
@@ -166,6 +177,7 @@ class TestSamples(unittest.TestCase):
         )  # The image resource doesn't exist
         self.assert_sample("property")
         self.assert_sample("property_binding")
+        self.assert_sample("responses", skip_run=not have_adw)
         self.assert_sample("signal", skip_run=True)  # The callback doesn't exist
         self.assert_sample("size_group")
         self.assert_sample("string_list")
@@ -257,6 +269,7 @@ class TestSamples(unittest.TestCase):
         self.assert_decompile("property")
         self.assert_decompile("property_binding_dec")
         self.assert_decompile("placeholder_dec")
+        self.assert_decompile("responses")
         self.assert_decompile("signal")
         self.assert_decompile("strings")
         self.assert_decompile("style_dec")