[BIP-182] Enable bb-rf-USD Gauge [Arbitrum]

PR with multisig payload

Summary:

Due to the recent vulnerability disclosure, the deployment of the ComposableStablePoolFactory-v3 is configured to address the potential issues related to Balancer’s previous composable stable pools (v2). This pool uses the new composable stable pool factory. bb-rf-aUSDC is Reaper Aave Boosted USDC, which means we’re using a linear pool to deposit USDC into a Reaper USDC Vault which only deposits into Aave. Reaper handles the autocompounding of any rewards which adds additional yield. For reference, Reaper is a fork of Yearn v2 run by the Byte Masons who are talented developers in their own right. In the absence of an Aave v3 compatible atoken wrapper this arrangement represents the best path forward, and arguably it’s better than using a wrapper since we get the additional compounding benefit.

bb-rf-aUSDT represents boosted USDT, and bb-rf-aDAI represents boosted DAI.

References/Useful links:

Link to: • Website • Documentation • Github Page • Communities

Protocol Description:

USDC is the dollar backed stablecoin issued by Circle. DAI is the decentralized overcollateralized stablecoin by MakerDAO. USDT is the dollar backed stablecoin issued by Tether.

Motivation:

This Aave boosted 3pool will form the cornerstone of our USD stable liquidity on Arbitrum. The boosted APR is quite high intrinsic yield to this pool that will persist even without our token incentives. The great migration, Balancer's pursuit of optimizing capitali efficiency for liquidity providers, and reaper's deployment line up perfectly for this to happen on Arbitrum.

Specifications:

1. Governance: Find more information about MarkerDAO governance here. USDC and USDT are centralized and don’t have governance.
2. Oracles: This pool only relies on the rate providers of the linear pools to inform when yield is earned.
3. Audits: See here.
4. Centralization vectors: There are centralization risks with USDC, DAI, and USDT, though the market has clearly accepted those as minor for now.
5. Market History: See here.
6. Value: We will earn the protocol fee on bb-rf-aUSD yield, plus trading fees. BIP-19 will incentivize TVL to continue to grow here with trading volume and this implementation will continue to draw in new volume, as well as showcase the power of these pool types.

Link to pool: 0xD65979f15cfB52E9a6a4f8DEA34c69c1568EA4A8 Link to gauge: 0x5b0C1b84566708Dd391Ae0FecE1a32e33682EE3d

Specification

The DAO Multisig 0x10A19e7eE7d7F8a52822f6817de8ea18204F2e4f will interact with the AuthorizerAdaptor at 0x8F42aDBbA1B16EaAE3BB5754915E0D06059aDd75 and call performAction with the GaugeController at 0xC128468b7Ce63eA702C1f104D55A2566b13D3ABD for the target(address) argument and using 0x3a04f900 followed by the gauge address 0x5b0C1b84566708Dd391Ae0FecE1a32e33682EE3d and the corresponding gauge type for the data(bytes) argument.

data(bytes) : 0x3a04f9000000000000000000000000005b0c1b84566708dd391ae0fece1a32e33682ee3d0000000000000000000000000000000000000000000000000000000000000004