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/comments/unicode.wren

@@ -0,0 +1,11 @@
+// Unicode characters are allowed in comments.
+//
+// Latin 1 Supplement: £§¶ÜÞ
+// Latin Extended-A: ĐĦŋœ
+// Latin Extended-B: ƂƢƩǁ
+// Other stuff: ឃᢆ᯽₪ℜ↩⊗┺░
+// Emoji: ☃☺♣
+
+// TODO(bob): What about combining characters?
+
+io.write("ok") // expect: ok

test/method/call_name_too_long.wren

@@ -0,0 +1,4 @@
+// Don't want to actually execute it.
+if (false) {
+  0.thisIsAMethodNameThatExceedsTheMaximumNameLengthOf64CharactersBy1 // expect error
+}

test/method/long_name.wren

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

test/method/name_too_long.wren

@@ -0,0 +1,5 @@
+class Foo {
+  thisIsAMethodNameThatExceedsTheMaximumNameLengthOf64CharactersBy1 { // expect error
+    "body"
+  }
+}