[prism] Dev prism builds for python and Python Direct Runner fallbacks.

[lostluck]

This change does two tasks:

• Enables Python SDK developers to have prism automatically build and run locally using local changes to Prism when using PrismRunner.
• Sets Prism to be attempted to be used in the Python DirectRunner in some circumstances.

The main change is to the prism_runner behavior when the SDK reports a .dev version.
In that case:

• Try to go install github.com/apache/beam/sdks/v2/go/cmd/prism to the binary cache directory.
• If that doesn't succeed, inspect the output for module errors
  • If there are no module errors, then the local version of prism couldn't compile, OR go isn't installed. Either way, this is a developer addressable error.
  • If there are module errors, then those modules don't have access to a version of Beam Go, so instead install the latest released version of prism.
    • This can be avoided by having a go.work file set up to direct Beam to a local version of the beam repo. This will be documented in a forthcoming SDK Development guide.

Arguably independently, is Attempt To Use Prism in the direct runner.

• This currently only happens if we can't use the FnAPI runner.
• If Prism fails on receiving the job, on job submission, then fallback to the DirectRunner instead.

Other changes are a refactor to reverse a few if blocks and return earlier, improving readability and reducing indentations.

Part of #32564

Fixes #32877.

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[damccorm]

Thanks! This LGTM once checks pass (https://cwiki.apache.org/confluence/display/BEAM/Python+Tips#PythonTips-LintandFormattingChecks may help)

[lostluck]

I discovered the root of my problem was using a newer yapf than Beam does, (0.40, instead of 0.29), so now I can have the formatting enabled on save, which will help! Local Linting on the other hand eludes me. I'm fortunately not tickling that as often.