Add Gtk.Scale mark syntax

tests/sample_errors/scale_mark_position.blp

@@ -0,0 +1,7 @@
+using Gtk 4.0;
+
+Scale {
+  marks [
+    mark (0, bottom_right),
+  ]
+}

tests/sample_errors/scale_mark_position.err

@@ -0,0 +1 @@
+5,14,12,'bottom_right' is not a member of Gtk.PositionType

tests/samples/scale_marks.blp

@@ -0,0 +1,9 @@
+using Gtk 4.0;
+
+Scale {
+  marks [
+    mark (-1, bottom),
+    mark (0, top, _("Hello, world!")),
+    mark (2),
+  ]
+}

tests/samples/scale_marks.ui

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<interface>
+  <requires lib="gtk" version="4.0"/>
+  <object class="GtkScale">
+    <marks>
+      <mark value="-1" position="bottom"></mark>
+      <mark value="0" position="top" translatable="true">Hello, world!</mark>
+      <mark value="2"></mark>
+    </marks>
+  </object>
+</interface>

tests/test_samples.py

@@ -165,6 +165,7 @@ class TestSamples(unittest.TestCase):
             for f in Path(__file__).parent.glob("samples/*.blp")
             if not f.stem.endswith("_dec")
         ]
+        samples.sort()
         for sample in samples:
             REQUIRE_ADW_1_4 = ["adw_breakpoint"]
 
@@ -191,6 +192,7 @@ class TestSamples(unittest.TestCase):
         sample_errors = [
             f.stem for f in Path(__file__).parent.glob("sample_errors/*.blp")
         ]
+        sample_errors.sort()
         for sample_error in sample_errors:
             REQUIRE_ADW_1_4 = ["adw_breakpoint"]
 
@@ -212,6 +214,7 @@ class TestSamples(unittest.TestCase):
         self.assert_decompile("property_binding_dec")
         self.assert_decompile("placeholder_dec")
         self.assert_decompile("responses")
+        self.assert_decompile("scale_marks")
         self.assert_decompile("signal")
         self.assert_decompile("strings")
         self.assert_decompile("style_dec")