Remove redundant Cheraw SSCn feature
There are two features used by the SSCn Cheraw model that are effectively identical except for a few differences in the 5th decimal places of the trace. Delete Cheraw (SSCn, GR).geojson id:2182. Also, when referenced in the correcponding rupture set, a down dip width of ~19km down dip width is assigned which is inconsistent with the ~17km DDW used for the other SSCN and the USGS features, so we'll update the DDW as well (although the rupture-set property overrides should proably be deleted across the board for 2023).
