test: refactor beforeExit tests

Combine and rename tests for the beforeExit event on process.

The naming now more closely follows the de facto conventions of the project.

The two tests were very similar and do not seem to benefit from being separate.

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• commit message follows commit guidelines

Affected core subsystem(s)

test process