Define the uPortal context name (e.g. 'portal/' or 'uPortal/') in one place

[drewwills]

I see a bunch of these...

          'SERVICE_LOC': {
            'aboutURL': '/portal/api/session.json',
            'sessionInfo': '/portal/api/session.json',
            'sidebarInfo': '/web/staticFeeds/sidebar.json',
            'newstuffInfo': '/web/staticFeeds/new-stuff.json',
            'context': '/portal/',
            'base': '/portal/api/',
            ...

[apetro]

Locally backlogged for MyUW Scrum purposes as MUMUP-3222.

[apetro]

Depending on how implemented, this is going to be an "API"-breaking change. Might be interesting to think through how to make this improvement in a backwards-compatible way so as to avoid forcing changes to adopter configuration on upgrade.