Load in normalisation weights from file.

[jatkinson1000]

Options depending on approach:

• Load in new single column weights for pure single-column net
• Load in full grid and select single column
• Read in and scatter to MPI

[jatkinson1000]

Currently in #14 We are using a single column emulator Which adopts the first approach.

This is following discussion in the developer meetings and other approaches can be explored once this has been shown to work.