Implement repooling functionality

We have the ability to go back and resequence samples that didn't yield enough reads the first time. This could and should be automated with the database. Conceptually, this will require:

1. Parsing demultiplexing stats output (I am working on some code for this, but it's not tested yet)
2. Making a decision on which samples to repool and at what quantity
3. Creating a pick list for these samples
4. Creating a valid sample sheet for the repool

#4 will require a keeping a couple things in mind. First, the possibility of sample name collisions—currently sample names only must be unique on a plate (or maybe in a study). Repooling could violate this. What to do? Second, the possibility of barcode collisions. We only *need* to enforce barcode combo uniqueness per lane. Repooling samples from multiple lanes raises possibility of violating this. Need to be aware and come up with solution.

Inizia esaminando il codice non testato per il parsing delle statistiche di demultiplexing menzionato nell’issue, quindi segui i workflow esistenti del database, della pick list e della sample sheet. Il lavoro è completo quando la decisione di repooling e la quantità sono automatizzate, vengono prodotte una pick list e una sample sheet valide e le collisioni tra nomi dei campioni e barcode vengono gestite con dei test.

Scritto dal modello di indicizzazione a partire dal testo della issue.