Feat: Multisig proposals with multiple outcomes

[arrudagates]

This can be implemented by following the standard threshold checks considering that all outcomes that aren't nay count towards aye, and then from there select the outcome with the most votes.

Total supply 50 tokens, thresholds for passing with 50% aye and 50% participation

• Nay | 10 votes
• Stake 100 TNKR | 15 votes
• Stake 200 TNKR | 25 votes
  This proposal would pass the thresholds as the sum of the outcomes' votes becomes aye.
  The outcome with 25 votes would be selected as it has the most votes.

One issue that needs to be addressed is deciding when to end the voting process, as even though it passes, with multiple outcomes we don't know if votes to those outcomes will change.

[arrudagates]

Requires #208 for this implementation to be fair, solving the issue of minimum proposal lifetime by allowing the multisigs themselves to decide how they want that to work.

[lana-shanghai]

Hey, I would be happy to take this one after 208 is completed