SRTPluginBase 4.5: A stepping stone release

[Squirrelies]

The goal of this issue is to track the effort to get the various SRT systems into a cohesive and consolidated state.

Currently we have the current main branch which is several years old. The SRTPluginBase repo which is disjointed compared to what is in the original SRTHost repo. A plugin manager that is separate from the host itself and has various UX quirks. On top of all of that, we also are targeting a quite old version of .NET and are coupled to some older nuget packages as well.

The goals of this issue are...

1. Update SRTHost to net10.0 (not net10.0-windows).
2. Update SRTPluginBase to net10.0.
3. Add a slim, debug host implementation for debugging in the SRTPluginBase repo. Tentatively called SRTPluginBase.Hosting.
4. Implement a basic WinForms UI to SRTHost for plugin management and updates, superseding SRT Plugin Manager.
5. Update documentation and examples to reflect newer design philosophies.