[lldb/crashlog] Add `-V|--version` option

This patch introduces a new option to the crashlog command to get the
the script version.

Since `crashlog.py` is not actually versioned, this returns lldb's
version instead.

rdar://98392669

Differential Revision: https://reviews.llvm.org/D131542



Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>