Convert stages to use card

[timja]

also:

• switch to tree view for consistency and remove old graph code
• disable live reload, it just infinitely polls even when all jobs have finished, not what we want here
• add support for expander going to a different page instead of a modal

Before

After:

[lppedd]

I don't like how the cards are horizontally compressed. Did you enable this behavior via CSS or are they like that by default?
On big screens it definitely makes sense to extend them to fill all the space that is available.
See also #277