Use consistent naming across the codebase

[KonradStaniec]

Currently naming across code base is a bit inconsistent and misleading.

For example

As an external user, I'd expect that by running stakercli unbond this condition would be fulfilled; however, that's not the case. After the unbonding transaction is confirmed, I'll need to run stakercli unstake to release the funds to my account.

Also stakercli unstake, should be called stakercli withdraw to be consistent with staker-cli withdrawable-transactions naming.