KeyData type moved to utils package to allow sharing between multiple packages.
Updated all commands and command tests to pass context object to KeyExists, KeyLock, keyUnlock, KeyRLock, and KeyRUnlock.
Create context object for each test in all test suites instead of just passing context.Background() to all functions that accept a context.
SetKeyExpiry and GetValue keyspace receiver functions now require context object to be passed.
Created adjustMemoryUsage function for key eviction for LFU, LRU, and Random eviction policies.
Updated all modules to pass context to SetKeyExpirty and GetValue functions.