Fixed functions taking lambda expressions to have the correct signature
Filters and order bys use now use mappings

A simple language that replaces any property names surrounded with curly braces in filters and order bys now allows queries to be more database agnostic.
The postgres repository now uses mappings

All queries now make use of the entity mappings and all filters and orderbys are implement the new query format
Fixed build error
Fixed build errors introduced in last commit