Add supports for fine-grained configurations

[luxploit]

Feature Request

Currently to have something that resembles triplet configuration, I had to write my own python script to dynamically generate 16 configurations that follow <target>-<mode>-<arch>, as I need to specify different targets depending on what I'm building for, which also is quite cumbersome to browse through to find the right one.

So instead of just one big "C/C++ Configuration" option, what there are 2 default "sub"-configurations, one for the build mode (ie. debug/release) and one for the build architecture (ie. x86/x64/arm64). Users can then if need be add additional options, to configure it further, which is great if you need fine-grained options.