Add support for SparkJob in the kubernetes dashboard

[foxish]

We want SparkJob to be a first class item on the dashboard.

[ash211]

Chatted with Anirudh about this today -- essentially this just means creating a "SparkJob" third party resource and creating one for each driver. It contains basically a URL for accessing the Spark UI, and possibly other metadata. Then frontends like kubernetes dashboard read that TPR and display the list of links in their webuis.

[foxish]

Ongoing discussion in kubernetes/dashboard#1599