Automated portfolio summary

[stufraser1]

Propose to automatic some of the portfolio summary / portfolio metadata, to draw this from the input files instead of being user-entered.
Helpful to users who don't know the data well, to summarise and check contents before running the transformation.

Could include: location summary, LOB, total TIV, number of rows, file name, file date as a check on version.

Possible Barriers: for a large dataset, will require importing and analysing the file earlier, and separately to the main transformation. Pre-validation would need to be defined for each model input format - needs to be defined in same way as data validation files?