DolphinQt: StickWidget and IRWidget check for changed x/y before signaling change

[malleoz]

This is a pretty inconsequential change, I just noticed this as I was skimming TAS-related code.

Even if your mouse moved ever-so-slightly as to not change the x/y position of the stick, or if you held down left-click and dragged your mouse off of the stick widget, it would continuously fire the ChangedX/Y signal as well as queue up a Qt re-draw for the widget.

I have no idea if this actually helps performance to any noticeable degree, but I just figured this is likely more beneficial than it could be harmful.
This appears to reduce window latency issues encountered when holding down frame advance and rotating the stick at the same time. It does not get rid of the latency, but definitely reduces it.

[JosJuice]

Sounds reasonable.

[malleoz]

After reviewing, this actually seems to help with latency issues encountered when holding down frame advance when TAS Input is the window-of-focus.

1. Hold down frame advance
2. Hold down left click and rotate stick
3. Notice latency increases over time as update() calls stack up

This PR seems to reduce the latency noticed in step 3. Doesn't fix it, but definitely limits it a bit.

[Pokechu22]

I assume this doesn't cause #11649 to regress? (It shouldn't from my understanding since this is the opposite direction, but it's worth double-checking.)

[malleoz]

@Pokechu22 I've just verified that, with controller enabled, using controller to adjust sticks and IR are correctly updated/reflected in the TAS Input windows.