Prioritise the smallest geo code given in the "best location" mechanism

[michaelwood]

As both the recipientOrganisation and beneficiaryLocation can have multiple locations within them, it would be good to use the one with the highest precision when determining the best known location for the impact of the grant.

An idea from @KDuerden would be to use the GSS code against the area size (e.g. in km^2) . We would then maintain a table that gives us a precision priority. e.g. GPS -> Post Code -> GSS E01 -> GSS E92 -> etc

[michaelwood]

There is also the possibility of adding the area's physical size in the geo lookups themselves rather than relying on the type. This data is generally available e.g. https://geoportal.statistics.gov.uk/datasets/2219f72d5b8042c496e47488efd04b16/about