Feature Request: Move getOnrampBuyUrl to separate package for those not using react

[nkosi23]

Describe the solution you'd like

The package npm i @coinbase/onchainkit pulls in quite a lot of dependencies, especially for people not using react, graphql & cie (in my case i use angular). It would be great to be able to use utility functions such as getOnrampBuyUrl without needing to pull in that many dependencies, leading to potential conflicts etc...

Describe alternatives you've considered.

I have resorted to copy and pasting the function getOnrampBuyUrl instead of installing the package.