RCM datasets does not show instrument mode

[xmichele]

ESACPE-1399
RCM datasets do not report the SAR mode [sar:instrument_mode] in the title as per rule:

[platformLabel] [sar:product_type] [sar:instrument_mode] [sar:polarizations] [datetime {ISO8601-TZ}]

In addition the field is empty in the stac Item

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 25.00000% with 6 lines in your changes are missing coverage. Please review.

Project coverage is 10.86%. Comparing base (e98f1f9) to head (be716da).
Report is 2 commits behind head on develop.

Additional details and impacted files

@@           Coverage Diff            @@
##           develop      #52   +/-   ##
========================================
  Coverage    10.86%   10.86%           
========================================
  Files          240      240           
  Lines        35726    35725    -1     
  Branches      3156     3158    +2     
========================================
+ Hits          3880     3882    +2     
+ Misses       31846    31843    -3     

Flag	Coverage Δ
unittests	10.86% <25.00%> (+<0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
...rs.Data/Model/Metadata/RCM/RcmMetadataExtractor.cs	12.83% <25.00%> (+0.54%)	⬆️

... and 1 file with indirect coverage changes