Stitching: add normalization by sample

TODO

• Add an option to normalize frames (radios or volume) by a sample (over axis 2)
• add test
• add doc

extra

at configuration file level

This will add the following section to nabu-stitching configuration file

[normalization_by_sample]
# section dedicated to normalization by a sample. If activate each frame can be normalized by a sample of the frame
# should we apply frame normalization by a sample or not
active = False | True
side = 'left' | 'right'
margin = 0  #  possible margin before sampling start
width = 50  # sampling width
method = 'median' | 'mean'

drawing of normalization by sample vocabulary