MeSH Descriptor DTOs

[stopfstedt]

this will help with performance on reporting, do this similar to courseDTO etc.

example:

school of medicine: give me all mesh terms associated with session terms 'lecture'. runs ca. 1:30mins on localhost, returns ~2,7K records with all fkeys. payload is ~2MB.

aside: check into the feasiblity of removing fkeys from mesh descriptors while serializing in the API.