Most of the changes are completely pointless renaming of constructor
arguments so that they do not use the same name as the type members,
but :shrug:

Closes #2015

The base was also renamed from `TestEventListenerBase` to
`EventListenerBase`, and modified to derive directly from the
reporter interface, rather than deriving from `StreamingReporterBase`.

Each of the two reporter bases now has its own header file, and
cpp file. Even though this adds another TU to the compilation,
the total CPU time taken by compilation is reduced by about 1%
for debug build and ~0.5% for optimized build of the main library.
(The improvement would be roughly doubles without splitting the TUs,
but the maintainability hit is not worth it.)

The code size of the static library build has also somewhat decreased.

Follow up: Introduce combined TU for reporters, and further split
apart the catch_reporter_streaming_base.hpp header into its
constituent parts, as it still contains a whole bunch of other stuff.

* Added some missing `noexcept`s on custom destructors.
* Fixed `std::move` being called on a const-reference.
* Initialized `ScopedMessage::m_moved` in class definition, instead
of doing so in constructors explicitly.
* Turned some `enum`s into `enum class`es.
* Initialized `StreamingReporterBase::currentTestCaseInfo` in class
definition.
* Some cleanups in SelfTest code.

TAP format requires all results to be reported.
Removed extraneous preferences function (handled by parent)
Incorporated fix from 3d9e7db2e0fff8fc2edcf59d24351f3937e3ac62
Simplified total printing

This means that code such as

```cpp
TEST_CASE() {
    SECTION("first") { SUCCEED(); }
    auto _ = GENERATE(1, 2);
    SECTION("second") { SUCCEED(); }
}
```

will run and report 3 assertions, 1 from section "first" and 2
from section "second". This also applies for greater and potentially
more confusing nesting, but fundamentally it is up to the user to
avoid overly complex and confusing nestings, just as with `SECTION`s.

The old behaviour of `GENERATE` as first thing in a `TEST_CASE`,
`GENERATE` not followed by a `SECTION`, etc etc should be unchanged.

Closes #1938