Exposing the absolute position of objects after parsing
Hi there!

I would like to suggest a minor improvement to `kaitai-struct`: it would be quite beneficial to have objects exposing their absolute position (from the `_root` stream), by showing their start and end positions.

According to @GreyCat , this feature already exists via the debug mode but is only available in Ruby, JS and Java. If this could be accessible to the other languages (at least Python and/or C++ :smile: ), that'd be awesome.
And `ksv` already uses that property (the `highlight` string at the bottom).

There would be a lot of potential uses for such feature, notably the fact that it would allow to generate from a template precise mutated version of one particular section declared in the KSY file.

Thanks again for the fantastic work!