Add Support for Coinbase Onramp

[jbowen93]

• This is something that might be worth kicking the tires on to see if it’s an intra day integration but is lower priority than the existing bridge + swap work.
• We’ll need to setup a developer account
• This seems to be part of their larger Onchainkit work
• They have a “fund button” react thing which may be a turnkey integration
• They’re working on a “fund card” which seems to be a window/modal and is hopefully a drop in React thing, they’ll share when that’s ready.

Call notes: https://www.notion.so/astria-org/Call-w-Coinbase-Onramp-1826bd31a90c8063bd27c3b4c285c09f?pvs=4