WIP chore(ci_visibility): collect module-level line execution and imports

[romainkomorndatadog]

NOTE: still very much a WIP

This explores changes necessary for coverage collection for the Intelligent Test Runner in order to be able to properly capture import-time dependencies on other modules.

To achieve this, the following are introduced:

• optional instrumentation of import statements to capture that a given file imported a given module
• optional capture of execution of module-level lines during coverage collection
• optional reporting of import-time covered lines for modules traversed during regular coverage

The pytest usage of the internal coverage library is updated to use the collection of import-time lines, resulting in expanded coverage for all tests (or suites if using suite-level skipping).

Checklist

• [ ] Change(s) are motivated and described in the PR description
• [ ] Testing strategy is described if automated tests are not included in the PR
• [ ] Risks are described (performance impact, potential for breakage, maintainability)
• [ ] Change is maintainable (easy to change, telemetry, documentation)
• [ ] Library release note guidelines are followed or label changelog/no-changelog is set
• [ ] Documentation is included (in-code, generated user docs, public corp docs)
• [ ] Backport labels are set (if applicable)
• [ ] If this PR changes the public interface, I've notified @DataDog/apm-tees.

Reviewer Checklist

• [ ] Title is accurate
• [ ] All changes are related to the pull request's stated goal
• [ ] Description motivates each change
• [ ] Avoids breaking API changes
• [ ] Testing strategy adequately addresses listed risks
• [ ] Change is maintainable (easy to change, telemetry, documentation)
• [ ] Release note makes sense to a user of the library
• [ ] Author has acknowledged and discussed the performance implications of this PR as reported in the benchmarks PR comment
• [ ] Backport labels are set in a manner that is consistent with the release branch maintenance policy