Update SUI Color Scheme colors' AutoProp.Name and ToolTip (#16544)

In the Settings UI's Color Scheme page (where you edit the color scheme itself), update the color chip buttons to include the RGB value in the tooltip and screen reader announcements.

Closes #15985
Closes #15983

## Validation Steps Performed
Tooltip and screen reader announcement is updated on launch and when a new value is selected.

src/cascadia/TerminalSettingsEditor/ColorSchemeViewModel.cpp

@@ -178,12 +178,26 @@ namespace winrt::Microsoft::Terminal::Settings::Editor::implementation
         Name(TableColorNames[index]);
         Tag(winrt::box_value<uint8_t>(index));
         Color(color);
+
+        PropertyChanged({ get_weak(), &ColorTableEntry::_PropertyChangedHandler });
     }
 
     ColorTableEntry::ColorTableEntry(std::wstring_view tag, Windows::UI::Color color)
     {
         Name(LocalizedNameForEnumName(L"ColorScheme_", tag, L"Text"));
         Tag(winrt::box_value(tag));
         Color(color);
+
+        PropertyChanged({ get_weak(), &ColorTableEntry::_PropertyChangedHandler });
+    }
+
+    void ColorTableEntry::_PropertyChangedHandler(const IInspectable& /*sender*/, const PropertyChangedEventArgs& args)
+    {
+        const auto propertyName{ args.PropertyName() };
+        if (propertyName == L"Color" || propertyName == L"Name")
+        {
+            _PropertyChangedHandlers(*this, PropertyChangedEventArgs{ L"AccessibleName" });
+        }
     }
+
 }

src/cascadia/TerminalSettingsEditor/ColorSchemeViewModel.h

@@ -63,12 +63,19 @@ namespace winrt::Microsoft::Terminal::Settings::Editor::implementation
         ColorTableEntry(uint8_t index, Windows::UI::Color color);
         ColorTableEntry(std::wstring_view tag, Windows::UI::Color color);
 
+        hstring AccessibleName() const
+        {
+            return hstring{ fmt::format(FMT_COMPILE(L"{} RGB({}, {}, {})"), _Name, _Color.R, _Color.G, _Color.B) };
+        }
+
         WINRT_CALLBACK(PropertyChanged, Windows::UI::Xaml::Data::PropertyChangedEventHandler);
         WINRT_OBSERVABLE_PROPERTY(Windows::UI::Color, Color, _PropertyChangedHandlers);
         WINRT_OBSERVABLE_PROPERTY(winrt::hstring, Name, _PropertyChangedHandlers);
         WINRT_OBSERVABLE_PROPERTY(IInspectable, Tag, _PropertyChangedHandlers);
 
     private:
         Windows::UI::Color _color;
+
+        void _PropertyChangedHandler(const Windows::Foundation::IInspectable& sender, const Windows::UI::Xaml::Data::PropertyChangedEventArgs& args);
     };
 };

src/cascadia/TerminalSettingsEditor/ColorSchemeViewModel.idl

@@ -34,5 +34,6 @@ namespace Microsoft.Terminal.Settings.Editor
         String Name { get; };
         IInspectable Tag;
         Windows.UI.Color Color;
+        String AccessibleName { get; };
     }
 }

src/cascadia/TerminalSettingsEditor/EditColorScheme.xaml

@@ -55,10 +55,10 @@
 
             <DataTemplate x:Key="ColorTableEntryTemplate"
                           x:DataType="local:ColorTableEntry">
-                <Button AutomationProperties.Name="{x:Bind Name}"
+                <Button AutomationProperties.Name="{x:Bind AccessibleName, Mode=OneWay}"
                         Background="{x:Bind local:Converters.ColorToBrush(Color), Mode=OneWay}"
                         Style="{StaticResource ColorSchemesColorButtonStyle}"
-                        ToolTipService.ToolTip="{x:Bind Name}">
+                        ToolTipService.ToolTip="{x:Bind AccessibleName, Mode=OneWay}">
                     <Button.Flyout>
                         <Flyout>
                             <muxc:ColorPicker ColorChanged="ColorPickerChanged"