Fix new lint errors introduced in Go 1.19.0

[modular-magician]

Go 1.19.0 appears to lint function and package headers expecting tabs in places where spaces were previously acceptable. Fix some templates to add a space between the package definition and code autogen header, and perform various other cleanups.

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Release Note Template for Downstream PRs (will be copied)

Derived from GoogleCloudPlatform/magic-modules#6398

[github-actions]

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