Frame limiting improvements

[sonninnos]

Description

This PR retries a few reverted changes, and some more (quite a lot for a single PR though, but they are related):

• Corrected fast-forward frame skipping to use display frame time as target instead of core frame time
• Extended fast-forward frame skipping to also be used in paused state (which renders at unlimited speed now without vsync)
• Adjusted menu navigation timings
• Don't do double frame skipping with Vulkan on fast-forward (WIN32 + fullscreen + vsync on)
• Allow disabling menu vsync forcing with existing "Throttle Menu Framerate" option (still on by default)
• Stop fast-forward and slow-motion on menu toggle
• Don't stop/start audio on menu toggle
• Moved midi_driver_set_all_sounds_off() to menu and pause toggle
• Don't pause menu sounds if paused manually
• Relocated audio reinit for menu sounds to always after reinit (find out later why the same reinit is not enough)
• Ensure menu sounds are loaded on menu sound toggle
• Cleanups

The crucial part is the new frame discarding system to limit paused menu and and paused state rendering to display refresh rate without any sleep shenanigans. Even if menu is rendered uncapped without vsync, only visible frames are shown, and menu navigation delays stay the same.

[LibretroAdmin]

Regression on macOS (on a Macbook Pro M1 2020) - screen refresh rate seems to be stuck at 56Hz/56fps, can never reach 60fps/60Hz with this. Will revert for now.