JSONReporter considers verbosity when listing tests

* Quiet verbosity provides just the test names
* Normal verbosity adds tags
* High verbosity add the source location of the tests

Listing tests with the quiet verbosity results in about 1/4 of the
previous output, which leads to measurably faster execution of
`catch_discover_tests` when it does not need tags for labels.
(If it does need tags, the output is about 1/2 of previous).

extras/CatchAddTests.cmake

@@ -253,10 +253,15 @@ function(catch_discover_tests_impl)
 
   make_temp_file_path(listing_output_path "${_TEST_WORKING_DIR}")
 
+  set(_Verbosity "quiet")
+  if (add_tags)
+    set(_Verbosity "normal")
+  endif()
+
   execute_process(
     COMMAND ${_TEST_EXECUTOR} "${_TEST_EXECUTABLE}" ${spec}
       --list-tests
-      --reporter json
+      --reporter "json::verbosity=${_Verbosity}"
       --out "${listing_output_path}"
       --order lex # Make sure the output order, and thus test registration order, is consistent across runs.
     OUTPUT_VARIABLE listing_output