UMIP 122 -Add Polygon `DerivativeFactory` as `Creator` in DVM registry

Reminder: Synthereum is a protocol to issue multi-collateralized synthetic fiat assets against liquidity pools. Liquidity pools hold USD-stablecoin such as USDC and are the sole Token Sponsor: a mint is a transaction where the liquidity pool self-mints a synthetic fiat with a collateral in USDC, and sell this synthetic fiat for USDC to the end-user, at the Chainlink price.

The [UMIP-34](https://github.com/UMAprotocol/UMIPs/blob/master/UMIPs/umip-34.md) has been approved by the governance, allowing us to launch our synthetic assets collateralized by USDC on the mainnet ($1M TVL, $700k of synthetic assets minted; we have capped the amount of synthetic assets that can be minted until more audits are conducted; the protocol has received two full audit from Halborn and Ubik.) 

Later on we have made a redeployment of the `DerivativeFactory.sol` and it has been approved by the governance in [UMIP-101](https://github.com/UMAprotocol/UMIPs/blob/master/UMIPs/umip-101.md). In that version we have done a bit of code cleaning and removal of unnecessary code. All the changes done can be seen in the formentioned UMIP.

Now the time has come for Jarvis to expand to L2 solutions starting with a deployment on Polygon Mainnet. There are no changes done to the `DerivativeFactory.sol` contract since the previously approved version in [UMIP-101](https://github.com/UMAprotocol/UMIPs/blob/master/UMIPs/umip-101.md).