Update S2 L1 tests for masking

[jeremyh]

• Expand the test datasets, as the packager now needs to read L1 data files for masks, not just the metadata.
• Support for Sinergise package layouts, to fix the Sinergise tests.
• Skip masks that are too small have data (fiona doesn't like the gml files ESA provides that are null)

[codecov]

Codecov Report

Attention: 35 lines in your changes are missing coverage. Please review.

Comparison is base (a666bca) 84.78% compared to head (6c84222) 84.38%.
Report is 4 commits behind head on develop.

Files	Patch %	Lines
eodatasets3/wagl.py	67.28%	35 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop     #321      +/-   ##
===========================================
- Coverage    84.78%   84.38%   -0.40%     
===========================================
  Files           26       26              
  Lines         4410     4503      +93     
===========================================
+ Hits          3739     3800      +61     
- Misses         671      703      +32     

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[geoscience-aman]

Have not tested. Looks okay. Thanks @jeremyh!