[BIP-219] Enable bb-t-USD Gauge [Polygon]

Transaction Payload https://github.com/BalancerMaxis/multisig-ops/pull/117

Summary: The Tetu Protocol has been actively building within the Balancer ecosystem, with tetuBAL serving as its primary Balancer-focused product. Tetu wants to leverage boosted pool functionality by introducing the bb-t-usd composable pool which consists of 3 liner pools (bb-t-USDC, bb-t-DAI, bb-t-USDT)

The underlying tokens are USDC, DAI, and USDT. Those tokens will be partially invested in the TETU4626 vaults (USDC, DAI, USDT) to earn yield from dFORCE / MESH / AAVE optimized according to the market conditions.

References/Useful links:

• Website - https://tetu.io/ 2
• Documentation - Introduction - Tetu
• Github Page - Tetu · GitHub
• Communities - Tetu

Protocol Description:

Tetu is an asset management protocol that implements automated yield farming strategy for users.

Motivation:

The implementation of linear and boosted pools is gradually enhancing Balancer's capacity to boost capital efficiency throughout the protocol. The robust boosted pool aligns with Balancer's objective to offer a secure platform for LPs to access external yield sources while simultaneously ensuring efficient liquidity for swapping. This approach benefits both LPs and the DAO, generating yield

Specifications:

1. Governance: Multi Sig - Tetu
2. Oracles: No
3. Audits: docs.tetu.io
4. Centralization vectors: n/a
5. Market History: Tetu token can be volatile in the certain market conditions.

Composable Pool: 0xb3d658d5b95BF04E2932370DD1FF976fe18dd66A Gauge: 0x28D4FE67c68d340fe66CfbCBe8e2cd279d8AA6dD