Basic functionality

• Add support for non direct conversion (i.e int to time.Time, int to string etc ...)
• Add support for time.Time in criterion
• Add support for conversion in criterion
• Add IN/NOT IN translation to go expression
• Add support for psedo column expr i.e FieldX + 10 / FieldZ

Extended functionality

• Add query options

  • at hoc select
  • indexed data select

• Add multi level output (currently mapper work ony leaf level)

• Add SQL function support

  • COALESCE
  • CASE/IF
  • DATE (FORMAT/SUB/ADD)
  • CURRENT_TIMESTAMP
  • UNNEST

• Add GROUP BY support

  • ARRAY_AGG
  • STRING_AGG