Project 1: UnknownJsonProperties is not populated

[warriordog]

Regression due to converter rewrite

[warriordog]

Solution may involve moving this to TypeMap

[warriordog]

System.Text.Json has a built-in overflow JSON feature, but it wont quite work since we convert into multiple subset entities. One sub-optimal workaround is this:

• Add internal overflow JSON property to ASEntity (needs custom contract)
• Re-add UnknownJsonProperties to TypeMap
• Populate UnknownJsonProperties from the union of all overflow JSON in the graph.

This works because all non-overflow properties will be missing from at least one entity, which means that the union set is equal to the set of unmapped properties. There's a major downside, which is performance. We have to convert every extra property multiple times, and then do an additional pass to compute the final set. That is far from ideal.

[warriordog]

Another option is this:

• Preserve the original JsonNode within the TypeMap
• When serializing, overwrite it with new values

Downside: special handling is needed to handle the case where a property is changed to null or another ignored value. This may not be possible.

[warriordog]

Done. All tests are now passing!