gcadapter: Tidy up compiler warnings

udp: Silence a C++20 deprecation warning

configure_general: Explicitly guard use_multi_core when applying setting

This is likely an oversight during a rebase. Guards use_multi_core to be only set when the global value is in use. It should not make a difference given the current code base, but makes the code sensible.

cmake: pass libusb include directory

Remnant of an early implementation.

CMakeLists: Enable usage of C++20 on Linux

This also fixes building on Linux with C++20, so we can enable it across
the board for all OSes that we officially support.

CMakeLists: Correct boost asio disabling define name

Previously the name of the define was missing the BOOST_ prefix.

CMakeLists: Disable concepts in boost asio

C++20 deprecates using the = lambda capture to implicitly capture the
this pointer. Instead, we must specify it explicitly.

This doesn't modify class instance state.

Ensures that the function always has returns in all control paths.

It's deprecated in C++20 to use = to capture the this pointer.

Instead, we can simply pass this as an argument to the thread
constructor.

vfs_real: Fix MoveFile

CMakeLists: Make use of /std:c++latest on MSVC

frontend: Add support to batch install files to NAND

Fix Discord invite link

AM: fix GetDesiredLanguage:

vk_rasterizer: Pass <pSizes> to CmdBindVertexBuffers2EXT

CMakeLists: Do not search for system libusb on macOS

Revert "Port citra-emu/citra#5441: "Common: remove a mod from AlignUp""

Port citra-emu/citra#5441: "Common: remove a mod from AlignUp"

In cases where the size is not a known constant when inlining, AlignUp<std::size_t> currently generates two 64-bit div instructions.
This generates one div and a cmov which is significantly cheaper.

Provides the buildbot with one builder that is always tracking the
latest version of the C++ standard, allowing us to progressively rectify
our code and amend any differences between standards over time instead
of waiting for a complete standard change, potentially breaking a lot of
code all at once.

service: Update function tables

KeyManager: Prevent writing of invalid keys

This has been fixed in Nvidia's public beta driver 451.74. The previous
beta driver will be broken, people using these will have to update.

cmake: drop dependency on QtOpenGL

CMakeLists: Update fmt to 7.0.1