Create a hook for intercepting serialisiation errors

[nrobi144]

Use-Case

We don't just want to provide a default value in case certain fields can't be parsed or are not present in the JSON. But also intercept these issues so we can log & monitor it, when it happens.

Example DSLs

1)

abstract class MyValue {
  @BuiltValueHook(<deserializationError>: true)
  static void _logError(MyValueBuilder b, Exception e, String key) => logger.logError(ParsingError(e, key))

or maybe even better would be to do the same globally

2) A global plugin that logs all deserialization exceptions 🤔

This is assuming if @nullable is used and if that field can't be parsed, the value will be null and now exceptions will be thrown

[davidmorgan]

This looks related to #1293.

I think catching DeserializationError is something you can already do? Either by wrapping your RPC handling code in try/catch or by installing a Zone error handler to catch them.