`SetupAxisLimitsConstraints()` doesn't apply constraint for autofit

If you're trying to fit the plot values in say [0, 100] range, and have something like:

```cpp
ImPlot::SetupAxes(nullptr, nullptr, ImPlotAxisFlags_None, ImPlotAxisFlags_AutoFit | ImPlotAxisFlags_RangeFit);
ImPlot::SetupAxisLimitsConstraints(ImAxis_Y1, 0, 100);
```

then all the data outside [0, 100] limit is ignored during the fitting. For example, if all the data is in [0, 2] range, but one data value is 200, then this 200 value is ignored and the plot is fitted in the [0, 2] range and not in [0, 100] as it's supposed to.

I think the problem is in `ExtendFitWith()` function (possibly `ExtendFit()` has the same problem), as it should be something like this:

```cpp
inline void ExtendFitWith(ImPlotAxis& alt, double v, double v_alt) {
if (ImHasFlag(Flags, ImPlotAxisFlags_RangeFit) && !alt.Range.Contains(v_alt))
return;

// Current check
// if (!ImNanOrInf(v) && v >= ConstraintRange.Min && v <= ConstraintRange.Max) {
// FitExtents.Min = v < FitExtents.Min ? v : FitExtents.Min;
// FitExtents.Max = v > FitExtents.Max ? v : FitExtents.Max;
// }

if (!ImNanOrInf(v)) {
if (v < ConstraintRange.Min) {
FitExtents.Min = ConstraintRange.Min;
} else if (v > ConstraintRange.Max) {
FitExtents.Max = ConstraintRange.Max;
} else {
FitExtents.Min = v < FitExtents.Min ? v : FitExtents.Min;
FitExtents.Max = v > FitExtents.Max ? v : FitExtents.Max;
}
}
}
```