fix(internal/postprocessor): add scopes to all appropriate commit lines

[noahdietz]

Adds the scope, if the API directory changed is one configured for gapic generation, to all commit lines inside of a nested commit.

The go-yoshi release-please strategy will only include a commit line from a nested commit if it has a scope and one that matches the module up for release.

Note: not all commit lines in the test data get scopes now - some have nested commits for modules that aren't actually configured for gapic generation anymore i.e. batch/v1alpha1.

Also fixes an issue where we'd get a double bang (internal link) for breaking change commit lines that received scopes (which is now going to be all of them instead of just the first).

[quartzmo]

Note: not all commit lines in the test data get scopes now - some have nested commits for modules that aren't actually configured for gapic generation anymore i.e. batch/v1alpha1.

How hard would it be to update the tests to process only modules that are currently configured? The un-scoped commits seem like a potential source of confusion for future maintainers.

[noahdietz]

How hard would it be to update the tests to process only modules that are currently configured? The un-scoped commits seem like a potential source of confusion for future maintainers.

Yeah, I hear you, took me a bit of digging...I think we want to keep them though, they do exercise a condition in the code.