[BIP-928] Orderly Winddown of Balancer and Distribution of the Treasury

Summary

TL;DR - I propose an orderly winddown of Balancer: no new business development, a phased sunset of the protocol with a defined exit window, and the DAO closed to the extent legally and practically possible. - The treasury goes to BAL holders in kind and pro rata, after setting aside what the winddown still needs to spend, in two rounds and a final sweep. Round one opens at the end of May 2027: holders burn their BAL and receive their share of the treasury. Round two is an airdrop to the...