Description in href should not be empty

[jjrom]

Describe the issue
Link element in assets object or links array can have an empty "description". This is not valid from STAC point of view

Expected behavior
If a link has no description then the "description" property should not be returned

Additional context
Exemple https://api.dive.edito.eu/data/catalogs/copernicus-marine-products/copernicus-marine-product-SST_BAL_SST_L4_NRT_OBSERVATIONS_010_007_b