C-Salt v0.11.0: `Pkg` and DX Overhaul and Refactor

What's Changed?

• Stripped out cl and clang-cl support to reimplement later.
• Made many fields in Salt.toml optional, such as compiler, build_sys, build_sys_ver, etc.
• Added --mode for manual override in csalt build. Uses managed to call upon the CMakeLists.txt present if there, and fresh to re-generate it in the cache directory.
• Removed contents of build/ upon csalt clean along .csalt/.
• Added --zig-target to csalt build.
• Added pkg unit to utilize installed packages via pkg-config.
• Added ability to use custom compiler and linker flags with CMakeLists.txt, although not fully implemented or tested.
• Renamed --debug to --verbose.
• Added package manager help messages if pkg-config failed.
• Fixed dyn for macOS, extdyn is still up for contention.
• Added more binary installation options.

In-development Notice

This is not a stable version. Everything is subject to change, and may potentially break. Do not use this on already existing C repositories until you have copied it for C-Salt to use.