Add extensibility for IColumnParameter to custom data sources and data extensions

[trgibeau]

Column parameters offer ways to customize a column. Some of these are hard-coded into WPA at the moment. For example, the DataTableGenerator.GetDefaultPresetParameterForType() will generate default column parameters for Timestamp and TimestampDelta.

It makes sense for a developer to want to specify a default IColumnParameter as part of a column configuration, and to create their own IColumnParameter classes.

Note, we need to update WPA to support the feature

[trgibeau]

Not needed for v1.0, but consider for v1.1