AK: Move String::~String() and String::destroy_string() to StringBase

Author: https://github.com/DanShaders
Commit: 1b09a1851e
Pull-request: https://github.com/SerenityOS/serenity/pull/21661
Reviewed-by: https://github.com/ADKaster
Reviewed-by: https://github.com/alimpfard
Reviewed-by: https://github.com/kleinesfilmroellchen
Reviewed-by: https://github.com/trflynn89

AK/StringBase.cpp

@@ -73,4 +73,10 @@ bool StringBase::operator==(StringBase const& other) const
     return bytes() == other.bytes();
 }
 
+void StringBase::destroy_string()
+{
+    if (!is_short_string())
+        m_data->unref();
+}
+
 }