[MyMeta] Add support for xDAI & Polygon DAOs

[peth-eth]

Right now, the profile pages are displaying DAOHaus DAOs & NFTs on Ethereum mainnet.
With the increasing fees on mainnet, both DAOs & NFTs are rapidly moving to xDAI & Polygon.
We should add support for xDAI & Polygon.

[mattcan]

This is a list of DAOs across mainnet, xDai, and Polygon on a users profile page. A large number of these DAOs have no title or logo. There is also no marker to identify network. Going to pitch this in the design channel but possible solutions:

• if title is missing, use Moloch contract address
• if title is missing, use Unknown DAO
• create mini network bands on DAO avatars (I'm thinking like the old 'Fork with Github' bands)
• change the background colour of the DAO avatars dependent on network

We'll have some of the same problems when it comes to the /players page too.

[mattcan]

Some notes for myself:

• Opensea API (what is being used for NFT data) doesn't seem to report network information though it may support Polygon
• looked at a couple Moloch contracts with no title on the xDai chain, they don't seem to have the Register event in history but need to dig more
  • should also check with DaoHaus subgraph team for insights
  • after reading a few contracts, I am 90% sure that a DAOs name is not part of the contract and actually is based on the Register event of the factory contract. Still want to check in with DaoHaus to be 100% sure
• DAO icons are hardcoded, which kind of makes sense. We could use this to show network logos when no matching avatar is available

[mattcan]

PR for backend change which adds xDai and Polygon DAOs: #643

[mattcan]

I split the NFT work into another issue so I don't block progress while working on DAOs and because it seemed unrelated, at least from a data source perspective. See #647 for NFTs