Add support for static properties and methods (#28)

* x

* Add support for static properties and methods.

tests/ProxyInterfaceSourceGeneratorTests/Source/Human.cs

@@ -1,12 +1,7 @@
 namespace ProxyInterfaceSourceGeneratorTests.Source
 {
-    public class Human : Animal
+    public class Human
     {
         public bool IsAlive { get; set; }
     }
-
-    public class Animal
-    {
-        public bool X { get; set; }
-    }
 }

tests/ProxyInterfaceSourceGeneratorTests/Source/IPerson.cs

@@ -1,6 +1,6 @@
 namespace ProxyInterfaceSourceGeneratorTests.Source
 {
-    public partial interface IPerson
+    public partial interface IPerson : IHuman
     {
     }
 }

tests/ProxyInterfaceSourceGeneratorTests/Source/PersonExtends.cs

@@ -4,6 +4,13 @@ namespace ProxyInterfaceSourceGeneratorTests.Source
 {
     public class PersonExtends : Human
     {
+        public static string StaticMethod(int x, string y)
+        {
+            return "test";
+        }
+
+        public static string StaticString { get; set; } = "500";
+
         public string Name { get; set; }
 
         public string? StringNullable { get; set; }