Add spatial resolution to the properties for easier filtering possibilities

[Tschoun]

Describe the bug
There is currently no metadata in the collection that allows the user to filter for only the 10m images vs the 20m images in the collection. The spatial resolution is only part of the file/asset name.

Current filtering process

var S2_col = ee.ImageCollection('projects/satromo-prod/assets/col/S2_SR_HARMONIZED_SWISS')
                .filterDate(start_date, end_date)
                .filterBounds(aoi)
                .filter(ee.Filter.stringEndsWith('system:index', '10m'))

Expected behavior

var dataset = ee.ImageCollection('projects/satromo-prod/assets/col/S2_SR_HARMONIZED_SWISS')
                  .filterDate(start_date, end_date)
                  .Filter.bounds(aoi)
                  .filter(ee.Filter.eq('pixel_size_meter', '10'));

[davidoesch]

Add this to the existing assets in projects/satromo-prod/assets/col/S2_SR_HARMONIZED_SWISS/

[Tschoun]

Added 'pixel_size_meter' to all swissEO S2-SR assets in the SATROMO/prod environment.