Missing error handling in Serializer.skip and related streams

Serializer.skip should fail with an exception if it cannot skip the requested amount of bytes.

One example problem case is when a literal's data has been serialized as a Float array but it is being deserialized as a Double array. The current implementation of org.simantics.databoard.util.binary.InputStreamReadable will simply report skipBytes(int|long) as having skipped the exact amount of bytes it was given, not the amount of bytes reported to have been skipped by its backend input stream.