feat: CodegenApp

[jayhack]

Enables setting up an app that:

• Creates a cached codebase (amenable to memory snapshotting)
• Responds to trigger events, e.g. Github PR created

Like so:

cg = CodegenApp(...)

@cg.github.event('pull_request:created')
def run(event: PRCreatedEvent):
	codebase = cg.get_codebase('codegen-sh/codegen-sdk')
	codebase.checkout(event.pr.head.sha)
	...
	cg.github.client.add_comment_to_pr(event.pr.number, "hello, world!")

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✅ jayhack
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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

✅ All tests successful. No failed tests found.

Additional details and impacted files

[github-actions]

🎉 This PR is included in version 0.33.0 🎉

The release is available on GitHub release

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