Introduce deterministic property execution, built-in generators, shrinking, replayable seeds, and a separate Progmasoft-owned header API while preserving Catch2 compatibility targets and the C++14 engine baseline.

Add Bazel, Meson, Xmake, and Premake integration and tests alongside the existing CMake build. Replace Linux-only workflow coverage with Windows and macOS jobs and document the Catch2/Catch3 distinction.

Three misspellings in comments: "reuired" -> "required",
"ambigous" -> "ambiguous", "neccessarily" -> "necessarily".

Per docs/contributing.md, the amalgamated files under extras/ are left
untouched even though they carry the same typos.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

The new implementation keeps track of found escape codes in a separate
vector, which has two advantages:
1) The handling of inputs without any escape codes is much faster. As
   this will be the case for majority of inputs, this should provide
   nice speedup all around.
2) We no longer mangle unrelated 0xFFs in the user-provided input.

Closes #3199

Catch2 defaults to random test execution order, which has to process
all tests present in the binary, even if they will be filtered down
to just 1 later. For the `SelfTest` binary, the overhead from this is
about 20% in Debug configuration and 5% in Release.

By registering the CTest tests with `--order decl`, we avoid this
overhead.

Previously we would check if the tag is special to validate that it isn't
reserved, and then to actually get the test case properties. We also did
the first check in particularly terrible order, leading to a lot of wasted
work.

The new implementation does property extraction while checking validity,
and is structured to avoid as much work as possible by early checks.