Message: execute::reinvest

This function checks the number of unlocked coins in the same atomic transaction that was harvested from delegator rewards.

It goes over the unlocked coins, checking if they are the relevant stake/bond tokens. In the case of stake.utoken, these coins are redelegated through a Cosmos message. In the case of stake.denom, these coins are burned. Otherwise, the coin is ignored.

A fee is sent to the protocol contract. It then removes the coins from the unlocked_coins that have been redelegated/burned.

Then the exchange rate is updated to be up to date with the newly received rewards.

There are no arguments supplied in this callback.