Fix ModKeys mapping allowing for keyboard shortcuts

[DarkDestry]

Issue

Current commented out implementation maps 2 keys to the same modifier key and call it separately.
Input state will flip flop between pressed and released when only 1 modifier key is pressed, resulting in UI slowdown due to repeated input event handling.

Fix

Use a single io.AddKeyEvent() call to activate modifier key when either modifier key is pressed.
Also passthrough the individual modifier keys itself so input handling can be done on the imgui layer for those specific keys.
Additionally map the OSX command key to super.

Resolves #78 and #75

Workaround

If you are here due to copy paste or any modifier key shortcut not working and the fix is not merged, place the following code into any Update() function.

void Update()
{
    var io = ImGui.GetIO();
    
    io.AddKeyEvent(ImGuiKey.LeftShift, Input.GetKey(KeyCode.LeftShift));
    io.AddKeyEvent(ImGuiKey.RightShift, Input.GetKey(KeyCode.RightShift));
    io.AddKeyEvent(ImGuiKey.ModShift, Input.GetKey(KeyCode.LeftShift) || Input.GetKey(KeyCode.RightShift));
    
    io.AddKeyEvent(ImGuiKey.LeftCtrl, Input.GetKey(KeyCode.LeftControl));
    io.AddKeyEvent(ImGuiKey.RightCtrl, Input.GetKey(KeyCode.RightControl));
    io.AddKeyEvent(ImGuiKey.ModCtrl, Input.GetKey(KeyCode.LeftControl) || Input.GetKey(KeyCode.RightControl));
    
    io.AddKeyEvent(ImGuiKey.LeftAlt, Input.GetKey(KeyCode.LeftAlt));
    io.AddKeyEvent(ImGuiKey.RightAlt, Input.GetKey(KeyCode.RightAlt));
    io.AddKeyEvent(ImGuiKey.ModAlt, Input.GetKey(KeyCode.LeftAlt) || Input.GetKey(KeyCode.RightAlt));
    
#if UNITY_EDITOR_OSX || UNITY_STANDALONE_OSX || UNITY_IOS
    io.AddKeyEvent(ImGuiKey.LeftSuper, Input.GetKey(KeyCode.LeftCommand));
    io.AddKeyEvent(ImGuiKey.RightSuper, Input.GetKey(KeyCode.RightCommand));
    io.AddKeyEvent(ImGuiKey.ModSuper, Input.GetKey(KeyCode.LeftCommand) || Input.GetKey(KeyCode.RightCommand));
#else
    io.AddKeyEvent(ImGuiKey.LeftSuper, Input.GetKey(KeyCode.LeftWindows));
    io.AddKeyEvent(ImGuiKey.RightSuper, Input.GetKey(KeyCode.RightWindows));
    io.AddKeyEvent(ImGuiKey.ModSuper, Input.GetKey(KeyCode.LeftWindows) || Input.GetKey(KeyCode.RightWindows));
#endif
}

[donxemari]

The workaround did the trick, thanks much!
Do you think it might be somehow related to the mouse wheel scrolling being extremely slow now?
I got these two bugs in the last official update.

[DarkDestry]

Do you think it might be somehow related to the mouse wheel scrolling being extremely slow now?

Mine scrolls fine so im not sure. Might want to create a reproducible sample and file it in issues.