Rename compiler visitor messages
First step in removing test suite and builder.

We want to be able to plug the runner in as a receiver to the compiler, when we
execute the steps.
Inject the receiver for compiling gherkin documents - no default
Executes by using the runner as the receiver for the compiler.
Remove `Test::SuiteBuilder`
Remove `Suite#execute`
Remove `Test::Suite`
Rename `Test::SuiteRunner` -> 'Test::Runner'