Change how we handle tertiary packages

[wrightky]

Abandon the repeated try/except stuff inside config and opt for a local try/except inside functions which, if failed, forward the user to another script that handles unavailable packages. Could be something like:

try:
    from chord import Chord
except ImportError:
    print_install_instructions('Chord')

[wrightky]

Fixed the try/except stuff, so now we just need a good catch-all install method for packages.

Create a requirements.txt file in a fresh environment, and set it up in a script with the additional jupyter lab extension commands.