Implements a manual and automatic update checker with support for both release and testing update channels, allowing users to stay as up to date as possible. It is fully compliant with privacy regulations around the world, as it stays completely silent and inactive until the user gives the Ok to connect to GitHub for the latest releases.
Adds a utility class and functions to load libraries and symbols from libraries somewhat safely. Libraries are immediately unloaded when the last reference to them is lost, so the shared_ptr should be stored if the library is actually needed.
Changes applied:
* Moved utility files to /util/.
* Removed unused #includes.
* Removed unused ::ffmpeg::tools function.
* Removed unused variables.
* Fixed missing parentheses in the version macro.
* Fixed missing override on virtual function overrides and removed unnecessary virtual keyword from them.
* Disabled additional warning for ATL headers on MSVC only.
* Replaced direct printf parameters with their macro equivalent.
* Replaced C-style casts with C++-style casts.
* Applied clang-format again after an earlier change to the CMake file broke the integration for it.
