The previous sanitizer support was implemented in a very rigid manner,
with the compile options available for each sanitizer type been preset,
and enabling of each sanitizer through a preset variable.

This change makes it so that setting of compile options can be set on a
per-sanitizer-type basis and then added to builds via functions. Use via
the legacy `USE_SANITIZER` is available, but deprecated.

This is also flexible enough to allow overriding of the compile options,
via variables either in-script or passed in via the command-line.

Results of checks for compile compatability are cached, reducing time
on subsequent builds, provided the associated compile options are not
updated.

Checks for sanitizer availability/compatability are no longer platform
dependent. It will check on all platforms.

While clang has the best support, GCC also supports a number of
sanitizers, so verify via new CI jobs.

For macOS, add jobs testing sanitizer works both with AppleClang and
Clang.

For Windows, add jobs testing the address sanitizer for MSVC, as no
sanitizer is known to work with Clang or Clang-CL.

Each C++ version macro now uses version-specific variables instead of
one general, to help prevent issues when changing versions and the
variable being accidentally being used for a different version across
configurations/generations.

When checking for the availability of a sanitizer, it now checks the link
options as well as the compile options.