Implement Metamask snap for offsetting transactions

[aspiers]

The next generation of Metamask will include a framework for plugins called snaps. (Currently this is only available in the metamask-snaps-beta repository.)

This is an ideal opportunity to implement a snap which allows Metamask users to offset the carbon emissions associated with any transaction they submit through Metamask, using the eth-co2 npm module to interact with the CO2ken smart contracts in this repository. If you are interested in working on this, please contact us!