FIAT On-ramp for users

[anxolin]

Description
Incorporate one service that allows you to buy crypto with FIAT for easy onboarding and new users.
Very likely, our part would be just educational and linking to a 3rd party service that complies with the regulations.

Ideally would be friendly enough for our targeted users. We should assume not everyone has the same knowledge about crypto, so we can try to forward users to the right place.

One early idea, just to start the conversations and to reiterate, is to have a "New in crypto?, make sure you educate your self before buying" banner or section (point to educational content, also make sure an user can understand that this is a DEX, Ethereum has a commission, and one simple wallet is MM or Gnosis Safe).
Another section could be "Buy crypto with FIAT"
Third section, could be, "I already have crypto", it would invite you to trade in CowSwap.

Regarding the service. I like Zerion approach:

I'm sure there's many other ideas out there, for example this is Bancor approach: https://beta.bancor.network/fiat

My assumption is, as long as the service does a proper KYC and comply with the regulation, I understand we can link to this service. We should evaluate if this is OK.

Context

https://gnosisinc.slack.com/archives/CAP80NUGM/p1629817297002700

Original issue gnosis/cowswap#1321 by @anxolin

[elena-zh]

closed for now. can be reopened once prioritized

[anxolin]

Agree, thanks for cleaning up