Coverage guided Fuzzing CI job template
Full context in [parent epic](&3226)
### Proposal
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Provide a CI job template (e.g. `Fuzzing.gitlab-ci.yml`) that users can include in their pipelines
- Similar to how we provide `DAST.gitlab-ci.yml` and `SAST.gitlab-ci.yml`.
For the MVC, detailed configuration of the input corpus or mutators is not required. Provide users enough flexibility for users to specify the high-level characteristics of the app to be fuzzed and then use a predetermined fuzzing configuration based on the type of application (e.g. HTTPS & PyTest as a framework)
After including the job template in their `.gitlab-ci.yml` file, allow users to define in the steps to:
* Build their app for coverage-guided fuzzing and/or point to where a compatible version of their app is
- _Question_: Can we determine this automatically for certain use cases?
- Override `CC/CXX` for C++ projects
- Override `gccgoflags` for Go projects
- Auto-add Ruby [Coverage](https://ruby-doc.org/stdlib-2.7.1/libdoc/coverage/rdoc/Coverage.html) for Ruby projects
* _Question_: Can we use QEMU or another DBI framework to fuzz apps without re-building them for instrumentation?
_Question_:
1. What parameters does a user need to provide to us?
1. Can we piggy back off of the unit tests?
1. Can we ask a user to provide us the test harness that would be used for fuzzing?
This should leverage the CLI mode of our fuzzing engine, rather than require the user interact with a GUI
The job _must_ be able to complete within the run of the pipeline and not [time out](https://docs.gitlab.com/ee/ci/pipelines/settings.html#timeout).
### Permissions and Security
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### Documentation
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### Availability & Testing
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What risks does this change pose to our availability? How might it affect the quality of the product? What additional test coverage or changes to tests will be needed? Will it require cross-browser testing?
Please list the test areas (unit, integration and end-to-end) that needs to be added or updated to ensure that this feature will work as intended. Please use the list below as guidance.
* Unit test changes
* Integration test changes
* End-to-end test change
See the test engineering planning process and reach out to your counterpart Software Engineer in Test for assistance: https://about.gitlab.com/handbook/engineering/quality/test-engineering/#test-planning -->
### What does success look like, and how can we measure that?
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### What is the type of buyer?
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### Is this a cross-stage feature?
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### Links / references
epic