[GSoC 2022 Work Summary]: Building Synfig with the MSVC Toolchain & automating the build process using Conan

[theartful]

This project can be neatly divided into two parts:

1. Automating the build process using vcpkg with Windows being the target platform and msvc being the target compiler.
2. Automating the build process using conan for both Windows (msvc) and Linux (gcc/clang).

The vcpkg part is done and merged with the following PR: #2725

The conan part is 70% done, with the work being in the following PR: #2667

I also took the liberty of trying to make synfig build with vcpkg under linux as well, with the work being in the following PR: #2825

I started working with conan, and switched to vcpkg later on. I found vcpkg to be much less powerful and less flexible than conan in all the right ways! I had a much easier time dealing with vcpkg overall.