Make time dim-attributes reachable through dimensions

Changes include :
* Adding a flag to ReferenceDimAttribute to know whether it is a join key or not. If not join key, it is used considered as denormalized field.
* Changes timerange function to take column as the first param instead of simple identifier. This will allow rewriter to know if the column has to be picked through a reference if it is denormalized.
* Fixes issues in DenormalizationResolver and JoinResolver wrt pruning tables and paths.