[ADD] slashpoint change

For any voter transaction (ie observation, errata tx, tss pool, keysign fail), we add a slashpoint. When the transaction gets consensus, we minus a slashpoint for each who were apart of that consensus. Make sure that those who make an observation/etc after the consensus, still get their slashpoint taken off, but it has to be in the same block as when the consensus was made, not after.