feat: add Sequence.list method to collect elements into a new List

Implements a new `list` method on the Sequence class that iterates over all elements and returns them as a freshly created List object. Includes documentation with usage example and a test case using a custom TestSequence class to verify correct behavior.

src/vm/wren_core.c

@@ -136,6 +136,14 @@ static const char* libSource =
 "\n"
 "    return result\n"
 "  }\n"
+"\n"
+"  list {\n"
+"    var result = new List\n"
+"    for (element in this) {\n"
+"      result.add(element)\n"
+"    }\n"
+"    return result\n"
+"  }\n"
 "}\n"
 "\n"
 "class String is Sequence {\n"