Timer improvements

[shuffle2]

• refactors Common::Timer to be much simpler and (hopefully) clear
• moves unrelated code out of Common::Timer
• Windows: disables some recent power throttling OS features. I'm not sure how effective this is, someone should test on laptop or something.
• internally uses std::chrono in most places

[Zopolis4]

Is this supposed to contain the move to C++20?

[shuffle2]

Is this supposed to contain the move to C++20?

I was testing to see if that would enable non-msvc to use the time zone components of chrono, but it did not. So that code is msvc-only for now.

[shuffle2]

A further improvement would be going through the codebase and wrapping the raw usages of Common::Timer::NowUs() in a similar way to protect against rollover, but I'm going to stop adding on to this PR now :)

[iwubcode]

My generic comment here is that the timer class is still holding onto C++98 (?) concepts with names that embed the time type into them, ex: SYNC_BUTTON_HOLD_MS_TO_RESET, NowUs, etc. Part of the beauty of chrono is that time math and time comparisons are just so intuitive. Probably shouldn't be this PR but I'd like for us to move to using chrono fully.

Otherwise this looks pretty good. Thank you for doing this!!!! Yay chrono. Hopefully one day we can migrate more of our code to std::filesystem too..

[shuffle2]

I only made the comment about PROCESS_POWER_THROTTLING_EXECUTION_SPEED a little more clear; i think the PR is ready :)

[piau9000]

This broke the emulator for a lot of people.
After this commit, the following message shows up when trying to open it:

[shuffle2]

update your vc++ redist https://aka.ms/vs/17/release/vc_redist.x64.exe
or https://aka.ms/vs/17/release/vc_redist.arm64.exe if you're on arm64

[piau9000]

Thanks. I'm gonna post it in the forums to the others that are having it too.