Move "GenericSchemeRegistry" to its own repo + npm package

For the DAOcreator, we'd like to allow users to pick from alchemy supported generic actions. In order to do this, we'd like to depend on a single npm package that has these files within it so we can add the "target contract" address to the dao-params.json that gets generated.

Having the types in the index.ts in the npm package would be nice too :)

https://github.com/daostack/alchemy/blob/dev/src/genericSchemeRegistry