Result: get columns by name

[benedeki]

Background

In the current version it seems Slick dos not support getting the column value by it's name in a direct SQL query (at least it seems so). It's positional.
It seems in principle it should be possible to access column values by column names. That would make the result type creation much safer, and easier to automate.

Feature

Add the ability to access the Slick SQL results by column name.