Refresh rate driven rendering tick logic (#3375)

* Implement sync interval and refresh rate API for RenderViewportWidget

Signed-off-by: nvsickle <nvsickle@amazon.com>

* Measure actual frame timings in the viewport info overlay.

Takes the median of the sum of (frame end - frame begin) to provide more a more representative view of when frames begin and end.

Note: Until VSync is internally supported by the event loop, this will produce nearly identical frame timings as the frame will spend as much time as needed synchronously waiting on a vblank.

Signed-off-by: nvsickle <nvsickle@amazon.com>

* Make frame timing per-pipeline, wire up refresh rate info to ViewportContext

Signed-off-by: nvsickle <nvsickle@amazon.com>

* POC: Frame limit pipeline rendering

Signed-off-by: nvsickle <nvsickle@amazon.com>

* Switch Editor tick to every 0ms to allow better tick accumulation behavior

Signed-off-by: nvsickle <nvsickle@amazon.com>

* Move RPISystemComponent to the tick bus, remove tick accumulation logic

Signed-off-by: nvsickle <nvsickle@amazon.com>

* Add `AddToRenderTickAtInterval` to RenderPipeline API

This allows a pipeline to update at a set cadence, instead of rendering every frame or being directly told when to tick.

Signed-off-by: nvsickle <nvsickle@amazon.com>

* Make ViewportContext enforce a target framerate

-Adds GetFpsLimit/SetFpsLimit for actively limiting FPS
-Calculates a render tick interval based on vsync and the vps limit and updates the current pipeline

Signed-off-by: nvsickle <nvsickle@amazon.com>

* Add r_fps_limit and ed_inactive_viewport_fps_limit cvars

Signed-off-by: nvsickle <nvsickle@amazon.com>

* Quick null check from a crash I bumped into

Signed-off-by: nvsickle <nvsickle@amazon.com>

* Fix off-by-one on FPS calculation (shouldn't include the not-yet-rendered frame)

Signed-off-by: nvsickle <nvsickle@amazon.com>

* Clarify frame time begin initialization

Signed-off-by: nvsickle <nvsickle@amazon.com>

* Fix TrackView export.

Signed-off-by: nvsickle <nvsickle@amazon.com>

* Address some reviewer feedback, revert RPISystem API change, fix CPU profiler.

Signed-off-by: nvsickle <nvsickle@amazon.com>

* Add g_simulation_tick_rate

Signed-off-by: nvsickle <nvsickle@amazon.com>

* Address review feedback, make frame limit updates event driven

Signed-off-by: nvsickle <nvsickle@amazon.com>

* Remove timestamp update from ComponentApplication::Tick

Signed-off-by: nvsickle <nvsickle@amazon.com>

Code/Editor/Core/QtEditorApplication.cpp

@@ -44,7 +44,7 @@ enum
 {
     // in milliseconds
     GameModeIdleFrequency = 0,
-    EditorModeIdleFrequency = 1,
+    EditorModeIdleFrequency = 0,
     InactiveModeFrequency = 10,
     UninitializedFrequency = 9999,
 };