Add new subclasses of StudentProgramAssociation to cover federal programs

There is evidence that a lot of the extension work in the field relates to EDFacts reporting. Given that, and given the Generate project work, the concept is to produce defined subclasses of StudentProgramAssociation for all the major federal programs included in EDFacts. This would include progams like McKinney-Vento Homeless, Free-and-Reduced Lunch, etc.

There is also evidence that this strongly compliance-focused data is getting sprinkled throughout the model (e.g. Student.HomelessPrimaryNighttimeResidence under 3.0) rather than added to a more logical location (e.g. data collected as part of a program participation).