Add categories to software packages

[gilbertozp]

Extend current "department" field to allow other categories, e.g.:

• science domain: divisions?, general (text)?, NA, agnostic
• department: applied math, computer sci, computational sci, data sci & tech (allow other administrative units like groups or area?)
• main functionality: math lib, linear algebra lib, application development lib, visualization, middleware, storage management, workflows, etc.
• distribution/usage form: downloads, web service, Web UI, desktop GUI + service calls, etc

[gilbertozp]

Start with open-ended approach (bucket of tags), except:

• department
• version