Enable ReadAsync testing and fault injection in db_stress (#11037)

Enable ReadAsync testing and fault injection in db_stress (#11037)

Summary:
The db_stress code uses a wrapper Env on top of the raw/fault injection Env. The wrapper, DbStressEnvWrapper, is a legacy Env and thus has a default implementation of ReadAsync that just does a sync read. As a result, the ReadAsync implementations of PosixFileSystem and other file systems weren't being tested. Also, the ReadAsync interface wasn't implemented in FaultInjectionTestFS. This change implements the necessary interfaces in FaultInjectionTestFS and derives DbStressEnvWrapper from FileSystemWrapper rather than EnvWrapper.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11037

Test Plan: Run db_stress standalone and crash test. With this change, db_stress is able to repro the bug fixed in https://github.com/facebook/rocksdb/issues/10890.

Reviewed By: akankshamahajan15

Differential Revision: D42061290

Pulled By: anand1976

fbshipit-source-id: 7f0331fd15ee33fb4f7f0f4b22b206fe801ba074