Remove all RenderComponent methods and replace them with additional overloads of Render method

[egil]

Let's simplify the "render" API surface to a single method, RenderAsync(). Instead of having RenderComponent() and SetParametersAndRender(), I just want a single method that users can recognize and should be obvious depending on the context. That means:

public class BunitContext // previous TestContext
{
  // ...
 
  public ValueTask<RenderedFragment> RenderAsync(RenderFragment renderFragment);  
  public ValueTask<RenderedFragment> RenderAsync<TComponent>(Action<ComponentParameterCollectionBuilder<TComponent>> builder);
}

public class RenderedFragment
{
  // ...

  // replaces SetParametersAndRender
  public ValueTask RenderAsync(Action<ComponentParameterCollectionBuilder<TComponent>>? builder = null);
}

At the same time, I want to make ComponentParameter internal. There is no good reason for users to use that type or the tuple overload. Just leads to unstable tests, and I should probably just have removed the option before v1, but kept it around for compatibility's sake.

[linkdotnet]

Done by #1111