api: fix unbounded access in getting analog state (#544)

## Link to GitHub Issue, if one exists
#0

## Description of change
Occasionally we would read a bad "vKey" for an analog axis and end up
accessing invalid memory (beyond the size of a vector) and potentially
crash or read junk values.

## Testing
Fixed based on minidump, this was a rare repro though.

src/spice2x/overlay/windows/config.cpp

@@ -1743,6 +1743,7 @@ namespace overlay::windows {
                     auto analog_name = analog.getName();
                     auto analog_display = analog.getDisplayString(RI_MGR.get());
                     auto analog_state = GameAPI::Analogs::getState(RI_MGR, analog);
+                    analog_state = std::clamp(analog_state, 0.f, 1.f);
 
                     // list entry
                     ImGui::ProgressBar(analog_state, ImVec2(32.f, 0));