Provide basic implementation of ITestBlock

Changing issue from original intent. Originally, this was to just provide an implementation of ITestBlock. I'm going to broaden this to a general "do v2".

We use some implementation of ILogger in the vast majority of test blocks. See if it makes sense to:
- Add ILogger to ITestBlock (potential issue of restricting how people want to consume ILogger in test blocks, since we support both property and constructor injection)
- Provide a basic ITestBlock implementation that has an ILogger attached in the primary use case (property injection). Allows people to use it or not.