Handle (new) metadata

GOAL

several information like motor names used... must be available in the bliss ebstomo file from tomo/ebs-tomo!147. This PR intend to benefit from it.

new behavior

try to reach instrument/tomo_config group. If find it: use it, If not and if version > X: warn the user. In both case roll back to using the motor provided in the configuration file and default paths to search.

TODO

• add some preprocessing to get the motor position when possible
• add an option to ignore using 'tomoconfig' section (insure backward compatibility and allow user to still redefine motor names...)
  • from python API
  • from configuration file
• add unit tests
• test on real dataset