Update and enhance list of available Gaussian basis sets

- [ ] Update the Dunning cc-pV*N*Z basis sets (see [ccrepo](http://grant-hill.group.shef.ac.uk/ccrepo))
- [ ] Add cc-pCV*N*Z basis sets (from e.g. [ccrepo](http://grant-hill.group.shef.ac.uk/ccrepo))