Summary:
Resolves https://github.com/facebook/rocksdb/issues/8014

- Add an assertion on `DB::Open` to ensure `db_options.max_open_files` is unlimited if FIFO Compaction is being used.
- This is to align with what the docs mention and to prevent premature data deletion.
- Update tests to work with this assertion.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8172

Test Plan:
```bash
$ make check -j$(nproc)

Generated TARGETS Summary:
- 6 libs
- 0 binarys
- 180 tests
```

Reviewed By: ajkr

Differential Revision: D27768792

Pulled By: thejchap

fbshipit-source-id: cf6350535e3a3577fec72bcba75b3c094dc7a6f3