CMake: Make coverage reports optional
For example distro packaging shouldn't need to check code coverage; now setting -DENABLE_COVERAGE=OFF
silences a bunch of CMake configure
spam which eventually results in -- Cannot enable coverage targets because neither lcov nor gcovr are found.
anyway:
-- Could NOT find Lcov (missing: LCOV_EXECUTABLE GENHTML_EXECUTABLE)
CMake Warning at /usr/share/cmake/CoverageReport/CoverageReportConfig.cmake:1 (find_package):
Found package configuration file:
/usr/share/cmake/Lcov/LcovConfig.cmake
but it set Lcov_FOUND to FALSE so package "Lcov" is considered to be NOT
FOUND.
Call Stack (most recent call first):
CMakeLists.txt:129 (find_package)