feat: extract common button style.

src/Ursa/Common/DialogButton.cs

@@ -0,0 +1,11 @@
+namespace Ursa.Common;
+
+public enum DialogButton
+{
+    None,
+    OK,
+    OKCancel,
+    YesNo,
+    YesNoCancel,
+}
+

src/Ursa/Common/DialogIcon.cs

@@ -0,0 +1,15 @@
+namespace Ursa.Common;
+
+public enum DialogIcon
+{
+    Asterisk, // Same as Information
+    Error,
+    Exclamation, // Same as Warning
+    Hand, // Same as Error
+    Information,
+    None,
+    Question,
+    Stop, // Same as Error
+    Warning,
+    Success,
+}

src/Ursa/Common/DialogResult.cs

@@ -0,0 +1,10 @@
+namespace Ursa.Common;
+
+public enum DialogResult
+{
+    Cancel,
+    No,
+    None,
+    OK,
+    Yes,
+}