fix(slash): do not handle / + shift/alt, support for ascii keyboard

[neSpecc]

The problem

1. Right now Toolbox is opening even when Slash is pressed in a combination with Shift or Alt.
2. Toolbox is not opening for Slash press in non-default keyboard layouts

Screen.Recording.2024-01-26.at.10.49.14.mov

Cause

1. We're checking all keyboard keys using event.keyCode property with is not working properly in some keyboard layout.
2. There was no check for Shift or Alt

Solution

1. To open Toolbox we now use event.key=/ to check exact "/" typed. So check for Shift or Alt is not needed, since key will be different in that case.
2. To open Block Tunes we now use event.code=Slash to check if slash-like key pressed with cmd. For example, in Spanish keyboard it will be cmd+-

Resolves #2597

[ilyamore88]

Control or meta keys

[neSpecc]

CMD+/ and CTRL+/ open Block Tunes — this behaviour stays the same.
Problem was in Shift+/ and Alt+/ — Toolbox won't be shown now, since "key" will be "?" or "÷" — we don't need to check Shift or Alt separately. Previously we checked keyCode which is the same for those chars.

[ilyamore88]

Oh, okay. Shift is a bit weird for me here, because in some layouts I can't type / without shift.