BlobInputStream should implement skip

[OrangeDog]

Describe the issue
InputStream has methods skip(long) and skipNBytes(long), which by default read and discard the given number of bytes. BlobInputStream should instead override this to call LargeObject.seek64, which will give better performance.

Driver Version?
42.7.2

[davecramer]

Thanks for the suggestion.
Pull requests are welcome.

[OrangeDog]

I don't see any existing tests for the class. LargeObjectManagerTest does a basic read but that seems to be it?
StrangeInputStream implements skip, but nothing ever calls it.

[vlsi]

I guess we do not have specific tests for skip as we used the default implementation.
Sure if we add a custom implementation, we'll need to cover it with tests.

The mix of read + mark + skip + reset might be problematic for testing.

[OrangeDog]

You have implemented mark, reset, and close, but there are apparently no tests for those. I am happy to add this feature, but I don't really want the burden of testing the whole thing from scratch. Unless I simply haven't found the tests?

[vlsi]

In fact, the current implementation of reset resets the cached data, so there's no much value in testing mix of read/mark/reset calls.

mark/reset is tested in org.postgresql.test.jdbc2.BlobTest#markResetStream