Implement `MemcachedClient` for enhanced load balancing and resilient connection management.

[dkz2]

The goal of this issue is to ensure optimal distribution of cache keys across multiple nodes. In order to achieve this we will implement a MemcachedClient that will maintain an array of MemcachedConnedction instances for different nodes, manage connection pooling to gracefully handle connections losses and integrate a customizable HashFunction for users to determine the appropriate node for a particular key. Our current MemcachedConnection structure will remain but its functionality will be enhanced by the client to better handle multiple nodes and deliver a more resilient caching solution.