Conversion of types in queries

[asgerhallas]

Some types needs to be converted before being projected to a column in sql server. Say we have a property named Consumption of type Energy, which can be converted to kWh like:

x.Consumption.KWh

To project this while still having a reasonable name for the column we can override the name:

.With(nameof(Consumption), x => x.Consumption.KWh)

But then when querying this we can no longer just use x.Consumption, but have to use the .Column() extension method like:

from x in xs
where x.Column<decimal>(nameof(x.Consumption)) == 100
select x

We would like to be able to be able to write:

from x in xs
where x.Consumption == 100.KWh()
select x

To do that we have to know - in the linq provider - that the projection (on the left) has been converted and then apply the same conversion to the value (on the right) before building the sql. I think the config could look like this:

.With(x => x.Consumption, x => x.KWh)

This could maybe also be used to fix issue #30 .