Debugger: Clean up std::{w,}string dumper

Change-Id: I224c0d02ebca40d394e2588465877f894ca9ded9
Reviewed-by: hjk <hjk121@nokiamail.com>
Debugger: Make reference types visible with LLDB

Change-Id: I0caf56da8bc542f8829f21e703a6f4beb7d0b88d
Reviewed-by: hjk <hjk121@nokiamail.com>