Catch CORRUPTION error code and attempt automatic repair and reopen, or at least provide users the ability to directly repair

[CMCDragonkai]

Specification

Our C++ code can throw an exception with the code indicating CORRUPTION. This means the user needs to attempt to repair the database before they try to open it. This is because dbOpen itself can fail.

We need to catch this and attempt the repairDb native function. However we need to come up with tests for this, what is an example of a broken database? Maybe mess with the files in it.

Additional context

• Introduce Snapshot Isolation OCC to DBTransaction #19 - came out of this PR to introduce SI
• https://github.com/basho/leveldb/wiki/repair-notes
• questions about leveldb::RepairDB google/leveldb#630

Tasks

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