Sse migration from text to http package

This should address most of #205 and does address #209.

As mentioned in #209.  I moved the original classes and then created subclasses with the same name in the text.sse package.  These sub classes are marked as deprecated and will be removed, but they should provide backwards compatibility via casting to their super classes for anyone that happens to be using them in explicitly in their code. 
My point was that we do not need both `SseOverHttpClientPipelineConfigurator` and `SSEClientPipelineConfigurator` (same for server).

So, we don't need to add `SSEClientPipelineConfigurator` to http package. Just fold it into `SseOverHttpClientPipelineConfigurator`

Alternatively, deprecate `SseOverHttpClientPipelineConfigurator` and just have `SSEClientPipelineConfigurator` in http package containing what it takes to run SSE.