feat: enforce maximum method name length of 64 characters in compiler

Add MAX_METHOD_NAME constant and validation in copyName() to prevent method names exceeding 64 characters. When a method name is too long, the compiler now reports an error and truncates the name to the maximum allowed length. Also update MAX_METHOD_SIGNATURE to be derived from MAX_METHOD_NAME and MAX_PARAMETERS. Add test cases for valid 64-character method names, names that exceed the limit, and a call to an overlong method name.

test/method/long_name.wren

@@ -0,0 +1,7 @@
+class Foo {
+  thisHasAMethodNameThatIsExactly64CharactersLongWhichIsTheMaximum {
+    return "result"
+  }
+}
+
+io.write(Foo.new.thisHasAMethodNameThatIsExactly64CharactersLongWhichIsTheMaximum) // expect: result