[feature] allow for non-string configuration-specific preprocesor definitions on CMakeToolchain

[guiserle]

Currently CMakeToolchain only allows for string literal definitions due to quotes included on this line of jinja template.
add_definitions(-D{{ it }}="{{ value }}")

This limits the hability to declare integer or other definitions on generate() method. I hope this could be easily workaround by removing the quotes from the jinja template and, instead, adding them on python string variable

• I've read the CONTRIBUTING guide.

[memsharded]

Hi @guiserle

#8645 should allow it, a bit more tricky than expected, but I think it makes sense, it is a valid request.

[guiserle]

Looks like a valid solution to me. Thanks for taking the request into account