Support different types for grouping columns in GroupBy Druid queries

Calcite 1.13 pushes EXTRACT and FLOOR function to Druid as an extraction function (cf CALCITE-1758). Originally, we were assuming that all group by columns in a druid query were of STRING type; however, this will not true anymore (result of EXTRACT is an INT and result of FLOOR a TIMESTAMP).

When we upgrade to Calcite 1.13, we will need to extend the DruidSerDe to handle these functions.