AK/Lagom: Modify TestSuite to return how many tests failed from main

This allows us to remove the FAIL_REGEX logic from the CTest invocation
of AK and LibRegex tests, as they will return a non-zero exit code on
failure :^).

Also means that running a failing TestSuite-enabled test with the
run-test-and-shutdown script will actually print that the test failed.

Meta/Lagom/CMakeLists.txt

@@ -177,13 +177,6 @@ if (BUILD_LAGOM)
                 # FIXME: Only TestJSON needs this property
                 WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/../../AK/Tests
             )
-
-            set_tests_properties(
-                ${name}_lagom
-                PROPERTIES
-                    FAIL_REGULAR_EXPRESSION
-                    "FAIL"
-            )
         endforeach()
 
         foreach(source ${LIBREGEX_TESTS})
@@ -195,13 +188,6 @@ if (BUILD_LAGOM)
                 COMMAND ${name}_lagom
                 WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
             )
-
-            set_tests_properties(
-                ${name}_lagom
-                PROPERTIES
-                    FAIL_REGULAR_EXPRESSION
-                    "FAIL"
-            )
         endforeach()
     endif()
 endif()