(2.7) Change schema/mapping related JsonParseExceptions to proper JsonMappingExceptions

[cowtowncoder]

Looks like CsvParser sends all failures as parsing exceptions, but it really should use mapping exception instead, if the problem is not with low-level CSV encoding (problems which are relatively rare) but rather has to do with mapping column values into logical property values.

Since this does change behavior slightly, it can not be made in a patch release and needs to go in 2.7.