Add Support for CIP-179 Polls

[Cerkoryn]

List of changes

• Add support for CIP-179 linked on-chain surveys on governance actions
• Add backend support to fetch and validate linked survey metadata for a governance action
• Add backend support to compute survey tally results from survey responses submitted in votes
• Add survey response metadata support to the governance action voting flow
• Add frontend support to attach a linked survey when creating a governance action
• Add frontend support to answer a linked survey while casting a vote
• Add frontend support to display linked survey details and tally results on the governance action page

Checklist

• My changes generate no new warnings
• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the changelog
• I have added tests that prove my fix is effective or that my feature works

Have been having quite a bit of trouble building and running GovTools locally, so I can't validate any of the items on the checklist. I'm hoping that another contributor who can build it might be able to help me out with these changes enough to get it running on one of the testnets at least? If we can get it to that point that I am happy to iterate on it further myself 😅

Right now I was able to verify a basic PoC on the frontend by stitching together various parts, but it's ugly and deviates from the intended development flow. This PR itself should be clean though, I just can't verify it easily 😰