further modularisation and functionalisation of the code

[TKMarkCheng]

Is your feature request related to a problem? Please describe.
At the moment, the analysis structure is too rigid. Reading in by plate and normalising by plate needs to change, especially if positive and negative control are shared between plates.

Describe the solution you'd like
Take a step away from plate based normalisation. Now aim to:

1. pick out the dilution series, where applicable and known
2. Allow the specification of negative/positive control origin by group.
3. Normalisation can be applied by series or by cell.

Describe alternatives you've considered
N/A

Additional context
Add any other context or screenshots about the feature request here.