Add support for staking transactions

[nooomski]

Gotten some feedback from potential users that staking would be great to implement as well. So, together with other open issues, it looks like ideally there would be several actions that one could do with a multisig:

• Send tokens
• Staking (Claim, Delegate, Undelegate, Redelegate)
• Create vesting account Add support for create-vesting-account #49
• Create authorization (pending ledger support)

So I'm wondering if perhaps we should just have the available actions listed, and once clicked, a new form pops up with the inputs that that Msg takes.

[webmaster128]

I created #99 to follow up tracking message types