Fix console not preventing hotkeys from firing / Clean up hotkey-input conflict.

• Fix mistake in rP25169 (similar to one in rP24215) that allowed hotkeys to fire while typing in the console.
• Prevent Alt+key to fire hotkeys in input boxes & console as that is often text input.
• Split the hotkey triggering logic in two: a preparatory phase & an actual firing phase.

This allows the GUI code to check which hotkeys are about to fire and selectively allow them to go through. This makes it easier to change hardcoded hotkeys, such as the console toggling one.

Differential Revision: https://code.wildfiregames.com/D3786