Fix issues with truncated files in raw sends

Fix issues with truncated files in raw sends

When receiving a raw send stream only reallocated objects
whose contents were not freed by the standard indicators
should call dmu_free_long_range().

Furthermore, if calling dmu_free_long_range() is required
then the objects current block size must be used and not
the new block size.

Two additional test cases were added to provided realistic
test coverage for processing reallocated objects which are
part of a raw receive.

Reviewed-by: Olaf Faaland <faaland1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes #8528
Closes #8607