separate out DataList and DataQuery
move DataObjectMap into own file
rename DataQuery DataQuerySQL.

DataQuery is now an interface, DataQuerySQL is the implementer
partial refactor to DataQuery

Moving SQL-specifics to dataquerysql; extending DataQuery interface
to support more methods; making DataList implement DataQuery
so it supports chainable operations as well.
testing pointer and struct cases before refactor
minor comments and doc updates
initial controller test