PartitionedTable preview columns not identified

[devinrsmith]

A PartitionedTable does not show which columns are "preview columns". An explicitly merged table does show that information. The following screenshots show an example.

Engine Version: 0.35.0
Web UI Version: 0.83.0
Java Version: 21.0.3
Barrage Version: 0.6.0
Browser Name: Firefox 127
OS Name: Linux
@deephaven/js-plugin-ui: 0.16.0

[vbabich]

This seems to be a JSAPI issue, moved to deephaven-core.