[tomoh5tonx] start creation of nx file from .h5.

TODO

• Read each tomo:x
• create the sequence
• split each sequence into a file and create a 'master file' to read them all
• add data virtual dataset
• add basic metadata (name, beam...)
• add image_key and image_key_control
• add rotation_angle
• add x_translation, y_translation, z_translation
• add some progress to clarify treatment
• make sure file is still valid if moved.
• add count_time information
• add file version (same for edftonx)

limitation from original .h5 file

• image_key not register in tomo_v2_external

• some unit missing

• counter is saved as a detector. Why ? -> how to know which node contains 'camera' and which don't ?

  -> have to filter the 'detector name'

• rotation is sometime named srot, sometime hrsrot !!! (and for projection both are recorded !!!!) So in this case the order of checking key matter !!!

• for reference: several frame, one srot value !!!