Structured validation errors

[micimize]

Instead of surfacing an error with just a string, the top-level InvalidDataException should expose the underlying field-specific errors. This would allow for form validation integrations, etc.

This could even just be the existing internal VerificationMeta mapping.

https://github.com/simolus3/moor/blob/8f069c86f42a5b0d40719773a2da14968b6409da/moor/lib/src/runtime/data_verification.dart#L70-L74

[simolus3]

I've added the map from the error too the InvalidDataException class.