Research Portis' credit card to xDai onboarding and see if it is possible to work with our crowdloan

[onggunhao]

• Portis has built an amazing credit card onramp to xDai.

Product

• The implication of this is that "normal" users without knowledge of crypto, can just swipe a credit card and "buy" a part of Ines loan
• The status quo requires users to (1) have metamask, (2) buy ether, (3) buy Dai, and then know how to use metamask to approve and transfer Dai into the smart contract
• As Portis is a wallet, users do not need to worry about key management
• Repayments can be routed directly to the users' Portis wallet. We can use either xDai or Dai for this (this is pending the repaymentRouter)

What is not clear to me

• If they use xDai to contribute to the crowdfund, how do we still create a "repayment share" for them in the main smart contract?
• Should we just isolate this, and do a "final write" to the smart contract once the crowdloan is complete?
• How do we prevent an overfunded loan?

cc @adibas03 @tspoff @djuanit0x