GH-5148 Introduce "soft fail" for corrupt ValueStore

[ebner]

GitHub issue resolved: #5148

Briefly describe the changes proposed in this PR:

• Improved use of a corrupted ValueStore by handling error situations in ValueStore.data2value() with SailException (previously it was possible to get an ArrayIndexOutOfBoundsException and IllegalArgumentException).
• Introduction of a new system property org.eclipse.rdf4j.sail.nativerdf.softFailOnCorruptData to enable "soft failure mode" and to avoid exceptions as described above. Instead, an instance of the newly introduced CorruptValue will be returned.
• This solves the problem of not being able to iterate (and in consequence, backup) over the NativeStore in order to save uncorrupted statements. Without "soft failure mode" the RepositoryConnection would be forcefully closed when hitting the first corrupted value.

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• my pull request is self-contained
• I've added tests for the changes I made
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[hmottestad]

Could potentially include data[0] at this point.

[hmottestad]

This is an old copyright header. See https://github.com/eclipse-rdf4j/rdf4j/blob/main/CONTRIBUTING.md#code-formatting

[hmottestad]

Any chance you would be interested in adding some info about this to our documentation?

I'm not sure where, but maybe at the end of the NativeStore section here:

rdf4j/site/content/documentation/programming/repository.md

Line 60 in d05b511

The NativeStore saves data to disk in a binary format which is optimized for compact storage and fast retrieval. If there is sufficient physical memory, the Native store will act like the MemoryStore on most operating systems because the read/write commands will be cached by the OS.

Could we also try to create a test? Maybe create a NativeStore, add data, verify that the data is there. Do a shutdown() and then modify the files on disk to make them corrupted. Then init() the store again and try to read the data.