[WFC] DOT #1321 - Introduce quadratic funding to the polkadot treasury spending

Purpose: Introduce quadratic funding (QF) as an alternative to the current treasury spending model in the Polkadot ecosystem.
How it Works:
- Projects share a fixed public fund pool.
- Community votes, calculated by the weighted square root of donations, determine the final distribution.
Benefits:
- Reduces the influence of large token holders.
- Encourages broader community support.
Challenges:
- Potential for Sybil attacks (fake accounts).
- Incentivizing donations when a public fund pool exists.
Implementation:
- Funding rounds with predetermined budgets.
- Projects apply and are reviewed by curators.
- Communities donate assets, and funds are distributed via child bounties.
Reputation System:
- Addresses have voting weights based on on-chain and off-chain activities.
Audit:
- Transparent fund distribution and voting weight information.
FAQ:
- QF is an alternative to, not a replacement for, OpenGov treasury funding.
- Projects can apply for both QF and OpenGov funding.
- Whales benefit from QF by improving treasury spending decisions.