[MC-266253] Controls menu calls "Alt Gr" key "Right Alt" on international keyboard layouts

The bug

As of 1.13, Minecraft can now detect international keyboard layouts and change the display names of keys in the Key Binds menu accordingly. However, this is not the case for the two Alt keys, which are named according to the US layout at all times, which is inconsistent.

How to reproduce

Have your keyboard settings configured to a non-US layout, e.g. UK
Bind controls to the "Alt" key and "Alt Gr" key
Observe

Expected results

The control bound to Alt would say "Alt" and the control bound to Alt Gr would say "Alt Gr" (or "Alt Graph").

Actual results

The control bound to "Alt" says "Left Alt" and the control bound to Alt Gr says "Right Alt". This should only happen for US keyboards and other layouts without Alt Gr.