make: use compiler switches to control warnings/errors behavior

[jstine35]

• Improves printf verification for lutro assertions when using clang compiler
• Consolidates warning behavior into makefile and vcxproj file
• Reduced impact to disable only one specific warning which is deemed "generally harmless" : use of the gnu varadic macro extension. All other warnings are enabled.

Note that printf formatting verification is not supported on the gnuc compiler.

On Validation in MSC

I discovered today that MSVC 2022 provides a new command line feature /MX: which works as a compact and streamlined solution to promoting warnings to errors from the vcxproj/props sheets. Prior to VS2022 this could only be accomplished by using #pragma directives, which were not available at the build-system level.

https://learn.microsoft.com/en-us/cpp/build/reference/wx-treat-linker-warnings-as-errors?view=msvc-170

However the printf validation of Microsoft's C compiler are ineffective: it conflicts with the printf redirection macro which is used to surface console logs to the VS output window (it was intended for C++ and does not allow printf validation in C99), and because of this, and given that clang-cl is preferred over Microsoft C, I favored the minimalist approach and implemented only clang-cl formatting options (which as an added benefit, are self-documenting).

Aside: The redirection to the VS Output window is itself a low-value behavior nowdays, thanks to drastic improvements and upgrades made to Windows Terminal applications since 2021 or so. Probably also worth scrapping.