Rename d1/d2 column in tests

[kgyrtkirk]

• TestDataBuilder defines d1/d2 columns
• DruidQuery could be affected by the presence of those columns - as they may interfere with the prefix selection
• DruidCorrelateUnnestRule removes a project fully while it operates - which may cause all underlying columns to appear

Introduction of DruidRelFieldTrimmer which could remove unused columns under Correlate cause lots of _ differences between the decoupled and the old planner as DruidCorrelateUnnestRule essentially undoes the trimming