cmake: Use progress output for tests

This means instead of printing at least two lines per successful test,
we overwrite one line again and again with the current status, and
for *failed* (i.e interesting) tests we print the output.

Makes test failures much more visible.

cmake/Tests.cmake

@@ -36,7 +36,7 @@ endif()
 add_custom_target(test
   COMMAND env CTEST_PARALLEL_LEVEL=${CTEST_PARALLEL_LEVEL}
           ${CMAKE_CTEST_COMMAND} --force-new-ctest-process
-          --output-on-failure
+          --output-on-failure --progress
   DEPENDS fish_tests tests_buildroot_target
   USES_TERMINAL
 )