MSVC conformant preprocessor flags are not used in compile of conformant tests

[diablodale]

The desired MSVC conformant preprocessor flags like /Zc:preprocessor are not applied on compile of depthai-core conformant tests.
From what I understand, it is because INTERFACE is used below. It should be PRIVATE or PUBLIC instead. I recommend PRIVATE.

depthai-core/tests/CMakeLists.txt

Lines 44 to 46 in 5cafb68

	target_compile_options(${test_name}_conforming INTERFACE "/experimental:preprocessor")
	else()
	target_compile_options(${test_name}_conforming INTERFACE "/Zc:preprocessor")

Setup

• Microsoft Windows [Version 10.0.19044.1526]
• VS2019 v16.11.10
• depthai-core develop 3a2961d

Repro

1. cmake config and build for x64, shared, Debug with all tests and examples to be built

Result

After the config, inspect the makefiles or ninja.build or compile_commands.json.
The /Zc:preprocessor and /experimental:preprocessor do not appear on the cl.exe options for conformant tests

Expected

The /Zc:preprocessor and /experimental:preprocessor appear on the cl.exe options for conformant tests