Replace type tags on PMap and PValue and use newtypes instead

[kozross]

Instead of the current tag-driven system, we would have something like this:

• PUnsortedMap
• PSortedMap
• PMintingValue (implies sorted, no mandatory Ada)
• PLedgerValue (implies sorted, mandatory Ada)
• PRawValue (no guarantees)

[t4ccer]

PMintingValue (implies sorted, no mandatory Ada)

You need to split these in two, V1 and V2 PMintingValue implies mandatory zero ADA and non-zero everything else, V3 PMintingValue implies no ADA entry at all, and everything else non-zero