This requires a bunch of different changes across the reporter
subsystem.
* We need to handle multiple reporters and their differing
preferences in `ListeningReporter`, e.g. what to do when
we mix reporters that capture and don't capture stdout.
* We need to change how the reporter is given output and
how we parse reporter's output destination from CLI.
* Approval tests need to handle multireporter option
A new flag, `--allow-running-no-tests` was added to override this
behaviour if exit code of 0 was desired.
This change also made `-w NoTests` obsolete, and so it has been
removed.
This greatly simplifies running Catch2 tests in single binary
in parallel from external test runners. Instead of having to
shard the tests by tags/test names, an external test runner
can now just ask for test shard 2 (out of X), and execute that
in single process, without having to know what tests are actually
in the shard.
Note that sharding also applies to test listing, and happens after
tests were ordered according to the `--order` feature.
A test runner already has a --durations option to print durations.
However, this isn't entirely satisfactory.
When there are many tests, this produces output spam which makes it hard
to find the test failure output. Nevertheless, it is helpful to be
informed of tests which are unusually slow.
Therefore, introduce a new option --min-duration that causes all
durations above a certain threshold to be printed. This allows slow
tests to be visible without mentioning every test.
Changes done to Nonius:
* Moved things into "Catch::Benchmark" namespace
* Benchmarks were integrated with `TEST_CASE`/`SECTION`/`GENERATE` macros
* Removed Nonius's parameters for benchmarks, Generators should be used instead
* Added relevant methods to the reporter interface (default-implemented, to avoid
breaking existing 3rd party reporters)
* Async processing is guarded with `_REENTRANT` macro for GCC/Clang, used by default
on MSVC
* Added a macro `CATCH_CONFIG_DISABLE_BENCHMARKING` that removes all traces of
benchmarking from Catch
