pycdlib-explorer: Add functionality for modifying files in place (#71)
pycdlib-explorer: Add functionality for modifying files in place (#71)

* pycdlib-explorer: Add functionality for modifying files in place

This exposes the ability to modify a file in-place in `pycdlib-explorer`.

To facilitate this:
- `do_ls`: now shows file lengths in bytes alongside file names
- `do_modify_file_in_place`: calls the `modify_in_place` API to replace a file, uses the file's on-disk length

Co-authored-by: Chris Lalancette <281cd07d7578d97c83271fbbf2faddb83ab3791c@openrobotics.org>
clalancette/pycdlib