Find an appropriate place for CPU_kernel_inliner_NONE.InlinerTest test

[scerzh]

CPU_kernel_inliner_NONE.InlinerTest is a test for addkernels utility which is invoked during MIOpen build process. The utility is not to be delivered to end users and not present in miopen-hip-clients package. But the test is put inside miopen_gtest app which is part of miopen-hip-clients package and when run by an end user results in failure due to missing addkernels:

apt install miopen-hip-clients
cd /opt/rocm/bin
./miopen_gtest --gtest_filter=*CPU_kernel_inliner_NONE.InlinerTest*

A workaround MIOPEN_INVOKED_FROM_CTEST was created to skip CPU_kernel_inliner_NONE.InlinerTest unless it is executed by

make check

or

ctest -R CPU_kernel_inliner_NONE.InlinerTest

Now the test is run on CI but skipped when an end user runs the tests.

This approach creates a category of only-for-CI tests, which should now detect the environment they were invoked from, unnecessarily complicates the test system and needs to be replaced by a more readable solution.