Merge topic 'ci-gcov'

f7b0ddbe92 gitlab-ci: add a series of jobs to perform coverage
cedd32892e ci: support setting a different test timeout for CI
da4a1ec2ff gitlab-ci: add support for running gcov-based coverage
61aed5e5f2 CTestCustom: ignore coverage results from coverage tests
7191d72acd Tests/EnforceConfig: clear the `CMAKE_BUILD_TYPE` environment variable

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !11245