* [cifuzz] Create validate method on BaseConfig
Use it to validate that either OSS_FUZZ_PROJECT_NAME
or BUILD_INTEGRATION_PATH is set.
Also use it to validate that workspace is set
(rather than duplicate code).
Add tests.
* Use env var hack to bypass valdiation
* fix
* fix
* fmt
* fix
* tmp
* fix
Also:
1. Support coverage builds.
2. Add an integration test for coverage builds and reports.
3. Refactor docker code so that there is less duplication in getting arguments for docker run, in particular when handling container (production) vs no container (testing).
4. Rename coverage.py to get_coverage_report.
5. Add tests for untested functions in docker.py
6. Add a test for get_fuzz_target_runner.