`shape` field is missing the `s3` prefix and is a list of dictionaries for `sral-wat` and `sral-lan` Items

[pjhartzell]

This is both a bug report and a question about what to do about the shape field in the Item assets. Example asset:

        "enhanced-measurement": {
            "href": "https://sentinel3euwest.blob.core.windows.net/sentinel-3/SRAL/SR_2_WAT___/2023/06/03/S3B_SR_2_WAT____20230603T002735_20230603T011320_20230628T180900_2745_080_130______MAR_O_NT_005.SEN3/enhanced_measurement.nc",
            "type": "application/x-netcdf",
            "description": "Enhanced measurement data file",
            "shape": [
                {
                    "time_01": 2466
                },
                {
                    "time_20_ku": 49175
                },
                {
                    "time_20_c": 47958
                },
                {
                    "echo_sample_ind": 128
                }
            ],

• The lack of an s3 prefix (should be s3:shape) is a bug (not consistent with other products)
• How to handle a s3:shape field when the netcdf contains variables with inconsistent sizes is the question. For reference, the Planetary Computer excludes the s3:shape field in sral-wat and sral-lan assets.