Support cold staking

[vctt94]

This PR depends on #2423

It supports cold staking and is a work towards #1491

[matheusd]

Very nice :P

Been wanting to get this in. We'll need to work on the specific encoding for the unsigned transactions (whether using my custom json format or a future PSDT binary format) but it's working as intended.

One small UI note is that I'd prefer not to show the "You bought [x] tickets" message, since that isn't true.

[vctt94]

Rebased

[matheusd]

Hmm, I'm currently getting a weird error when starting up a watching only wallet on this PR (blank page and a js console error):

fp.js:23 Uncaught TypeError: fn is not a function
    at fp.js:23
    at Array.map (<anonymous>)
    at fp.js:23
    at Connect.configureFinalMapState (connect.js:155)
    at Connect.computeStateProps (connect.js:142)
    at Connect.updateStatePropsIfNeeded (connect.js:204)
    at Connect.render (connect.js:340)
    at finishClassComponent (react-dom.development.js:17184)
    at updateClassComponent (react-dom.development.js:17134)
    at beginWork (react-dom.development.js:18653)

This is even after nuking node_modules and app/node_modules and re-installing via yarn.

Are you seeing this as well?

[vctt94]

That's probably because of the f5408a5 which had some selectors leftovers. I fixed it at 082ca49 and now rebased this PR again.

Can you retry it?

[matheusd]

Working as intended now!