Experimental compiler refactor

[matthewmueller]

I'd like to take one more crack at the compiler refactor. It's important to get this process right because all the generators will fit within this overall process. Writing generators is the easy part.

The goal is to:

• Transition from bud starting a long-running generated cli process that starts another long-running app process to bud optionally running a short-lived generated cli process, then running a long-running app process.

Additionally:

• Gather all the generators and runtimes into a simple framework/ directory

This will hopefully make the code base much easier to follow, without compromising on flexibility.

[CLAassistant]

All committers have signed the CLA.

[matthewmueller]

Woohoo, it's aliveeeeee. Just need to do a bit more cleanup and it's good to go!

[matthewmueller]

This PR concludes a large internal refactor I've been working on since launch. The goals of this PR:

• Make it easier to understand. The double generated binary building was something that often confused me.
• Make it easier to contribute. I'm so impressed with the contributions so far, with this refactor it should be even easier.
• Make it faster during development. By far the slowest step in the build process is running go build. If we didn't need to do the double-compile, it should be 2x faster.

In general, now that I'm starting to get a better understanding of what people are expecting from the framework, I can start moving the codebase more towards that.

The results of this PR:

• There's no more generated cli, we're just generating an app! We will find solutions when the time comes for all the planned features that led to the generated cli design.
• All generators and helper runtimes live in framework/, supporting packages that are needed by the generated code live in packages/, everything else goes in internal/.
• Tests are faster and less flaky because no more generated CLI and a pubsub system that will tell the test when the app is ready
• Tests are more end-to-end because they only support two commands: cli.Run and cli.Start.
• No more v8client/v8server, everything has been consolidated into the bud client/server that's run during bud run.
• Debug logging! Added --log=debug to bud and the test suite. Slowly passing the logger through the subsystems.

Since so much of the codebase has changed, I'm pretty sure there's going to be a few minor regressions, but we can address them as they pop up. The core workflows have remained unchanged.

This PR pretty much wraps up v0.2. Have a look at the discussion to learn more about next steps.