Validate token staking contract addresses

[nkuba]

It is expected that the TokenStaking contract from the threshold module is used by the beacon (RandomBeacon) and ecdsa/tbtc (WalletRegistry) modules. All three modules should use the same instance of the contract.

During development testing, it gave a lot of headache to figure out the problem where the client used beacon and ecdsa contracts packages that were set with old threshold contracts. But the client used a newer threshold contracts package.

Here we add a simple validation to check if the TokenStaking contract used by the beacon chain and the tbtc chain match the base chain.