Update Sample Data To Use New Namespace Format for Descriptors

Update descriptor xml files and all references to descriptors in the sample xml files to use the new format for descriptor namespaces.

The namespace must look as follows:

uri://[org indicator]/[name of descriptor]#[value]
Example: uri://ed-fi.org/AcademicSubjectDescriptor#Chemistry

Need to discuss whether URI encoding code values makes sense in an xml context. Should we even include spaces in code values? Should the Xsd change to required namespace for descriptor references?