Make output-damage test skip correctly
b1e56143 added a new case for output damage test, depending on color operations compositor capability. The capability depends on OpenGL ES extension presence. If the capability is not present, creating the headless output would fail, failing the whole test. Instead, the test needs to skip if the capability is not found.
This MR makes the test skip appropriately, but it also adds a new build option that turns skips into failures. The latter is used in CI to ensure no test will skip in CI.
Edited by Pekka Paalanen