Add normalizers for OSISAF data about metanorm

[akorosov]

Raw metadata from MET OSISAF:
https://thredds.met.no/thredds/dodsC/osisaf/met.no/ice/amsr2_conc/2020/07/ice_conc_nh_polstere-100_amsr2_202007121200.nc.ddx

[akorosov]

After sea ice concentration normalizers for sea ice type and sea ice drift should be added
Parameters:
sea_ice_x_displacement
sea_ice_y_displacement

sea_ice_classification

[opsdep]

Everything needed is written in a3466b7 except parameter assignment.

[akorosov]

@aanersc , I already wrote these names. See above.

[opsdep]

@aperrin66
Please have a look at this new normalizer, If you agree with in general, then I start to write some tests for it. Find it in 7849bf9 please.

[opsdep]

Dear @akorosov,

PLease check out the new normalizer of OSISAF from remote sensing point of view in order to deliver meaningfull results in 'get_platform' and 'get_instrument' methods of it. It is necessary to mention this aspect of work.

[akorosov]

For all products you can use:
pti.get_gcmd_platform('Earth Observation Satellites')

And these instruments:

https://thredds.met.no/thredds/catalog/osisaf/met.no/ice/conc/catalog.html
pti.get_gcmd_instrument('Imaging Spectrometers/Radiometers')

https://thredds.met.no/thredds/catalog/osisaf/met.no/ice/amsr2_conc/catalog.html
pti.get_gcmd_instrument('AMSR2')

https://thredds.met.no/thredds/catalog/osisaf/met.no/ice/drift_lr/merged/catalog.html
pti.get_gcmd_instrument('Earth Remote Sensing Instruments')

https://thredds.met.no/thredds/catalog/osisaf/met.no/ice/drift_mr/catalog.html
pti.get_gcmd_instrument('AVHRR')

https://thredds.met.no/thredds/catalog/osisaf/met.no/ice/edge/catalog.html
pti.get_gcmd_instrument('Imaging Spectrometers/Radiometers')

https://thredds.met.no/thredds/osisaf/osisaf_seaicetype.html
pti.get_gcmd_instrument('Imaging Spectrometers/Radiometers')