Testnet: Staking from bech32 addresses

[tohsnoom]

With SegWit activated on testnet, it appears that inputs on bech32 addresses will not stake blocks. I do not have any specific error messages or reasons why pinpointed yet, but there is a large percentage of the total supply of tPHR stored on bech32 addresses, to the point where one out of every 3 or 4 blocks should be staked by a bech32 address if it were able to do so.

My suspicion is that it is one of two causes, or some combination:

1. When the wallet selects staking eligible inputs, it is not finding bech32 addresses.
2. When bech32 addresses try to stake, they are failing one of the staking validation checks and therefore never able to submit a valid block.

I'd suggest we add some additional logging in the staking code to isolate the cause and determine how to get staking for bech32 addresses working.