Requried a minimum amount of REP to vote in favor of executing boosted proposals

[AugustoL]

Problem
The genesis protocol machine that we are using allows any the execution of any boosted proposal with any amount of positive votes, this means that if a boosted proposal reach the execution time with 1 REP it will be executed. We have been talking about this and we considered this a problem, we need to be able to set up a mimum amount of positive votes required for a proposal to be executed.

Solution
Modify the configuration parameter in the voting machine contract called queuedVoteRequiredPercentage to be an array of uints, having in the first index the queuedVoteRequiredPercentage and in the second index the boostedVoteRequiredPercentage.

Every time a boosted proposal will be executed the amount of % in prositive votes needs to be higher than boostedVoteRequiredPercentage

Additional context
DXDVotingMachine contract: https://github.com/AugustoL/dxdao-contracts/blob/dxdao-contracts/contracts/dxdao/DXDVotingMachine.sol