Untangle forcing 1x speed from "Fast-Forward Rate"

There isn't actually an option for forcing 1x speed: Sync to Exact Content Framerate actually forces "original" speed as requested by the core, but introduces obviously issues in platforms without an actual VRR screen. An actual method for forcing the core native refresh rate is to set "Fast-Forward Rate" to x1.0, but with that you obviously lose the ability to fast-forward when you need it.
Forcing "native" refresh rate (by setting Fast-Forward Rate to 1.0x) helps with frame pacing with non VRR but HRR screens. Tested on various Android devices and reduces a lot of stutterings and frame pacings issues typical of that platform too.
Took a briefly look at the code and seems that the value of the option "Fast-Forward Rate", "fastforward_ratio", is actually used for frame limiting too, as suspected.
Would be great to have a global option for forcing 1x speed without affecting the ability to fast-forward.

Search for fastforward_ratio and trace how it is used for frame limiting and fast-forward behavior. Define the separate global 1x/native-refresh-rate setting, then verify frame pacing and retained fast-forward behavior on the affected non-VRR Android cases described in the issue.