Allow biological samples as input

[s-andrews]

Can we allow submissions of raw biological samples from which libraries will be prepared.

This will involve:

1. Adding an additional input field of sample type, which will either be pre-prepared library, or will be a sample set to be prepared.
2. Creating a new configuration option for the type of available library prep. For each of these we need to associate it with one, or more, existing library types. Where we have multiple library types we'll actually make multiple samples, one for each library type.
3. Allow samples to be submitted without barcodes. These can be added later by the facility.