Add tickets screen

[JoeGruffins]

Breaking off of #28

I think the tickets screen should be a pager with one ticket per page. It should include:
ticket amount
pool's url
time/blockheight bought
status
revoke button if revocable
progress bar (like dcrdata) that shows time til mature status and switches to time til expiration, then time til spendable

[buck54321]

Before we get into shuffling through the details of individual tickets, we need a screen to get an overview of staking statistics. Ticket count, total locked, network stats, etc. Honestly, I see little value in looking at individual tickets. Decrediton provides that type of fine control for people who want it. If TD does provide that kind of control, it will need to be implemented carefully to keep things useful and simple. A ticket-per-page as primary ticket view is only good for a few tickets, then it becomes tedious. A list view first is better. Clicking a ticket in the list could stack a ticket detail screen though.

So the hierarchy could be something like

1. Ticket stats -> has button for list view
2. List view -> clicking row opens ticket detail
3. Ticket detail

[JoeGruffins]

The ticket stats will include network stats? Lock percent is shown on the main screen as well.

If you don't think we need the individual tickets, just a list with links that point to dcrdata and bring up dcrdata in the user's browser then?