Make keybindings with modifiers block keybindings with no modifiers

Currently, if two actions are bound to the same key, one with a modifier (Alt+E) and one without a modifier (E), both actions are activated when the key+modifier is pressed.

Example

Expected behavior
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* Bind "Strafe Right" to key "E"
* Bind "Show Map Window" to key "E" with modifier "Alt"
* Save
* Press "Alt+E"
* Map Window openes and character does not strafe right

Current behavior
--------------------
* Bind "Strafe Right" to key "E"
* Bind "Show Map Window" to key "E" with modifier "Alt"
* Save
* Press "Alt+E"
* Map Window open and character also strafes right