Treasury prototype

[roleengineer]

solves https://github.com/0xHabitat/mvp/issues/1

[marcocastignoli]

• double check UNIv2 LPT coefficent
• what if unstake cannot call decreaseVotingPower() ?
  • one solution could be to make decreaseVotingPower and increaseVotingPower immutable
• distinguish voting power struct from treasury (make general voting power struct between treasury and governace)
• check "hasVotedInActiveProposal" is called two times one by the stake contract and one by the diamond:
  • check the gast cost of hasVotedInActiveProposal
  • solution could be to restrict maximum amount of active proposal or elements in active proposals array

[marcocastignoli]

• extract check of destination in createTrasuryProposal in another function
• check gas cost of event TreasuryProposalCreated (so we can remove exp date)
• why activeproposalsid is an array and not a mapping?
• create a function to delete the proposal

[roleengineer]

activeProposalsId is an array, because there is no way to define, if the holder has voted in active proposals in a case of mapping (we don't know the list of keys that are non-default values)