Implement Delete Operation Support

[dkz2]

This issue will focus on implementing the delete command. The goal here is to create a new type of MemcachedRequest that correspond to the delete operation. Additionally, this issue includes updating our MemcachedResponseDecoder and MemcachedRequestEncoder to handle request/responses for delete operations. Unit tests for delete request construction and response parsing, as well as an unit and integration test with a Memcached server, and Finally adding API support to our Connection Actor.