Bug 453654

SUMMARY
It is impossible to bind key combination like <C-;> or <C-/>. It seems that generally it is not possible to bind Control with key that is not an alphabetic character. For example, if press <C-;> when cursor is in test area, I get `;`. I tried to add `key Semicolon+Ctrl : "\E[59;5u"` in my keytab file, but it doesn't work either – opening keytab settings shows that konsole interprets it as `+Ctrl`. It is possible, though, to bind such combination as shortcut in any KDE application. I know that at least kitty and alacritty does allow to send custom ANSI codes for these keystrokes. 

STEPS TO REPRODUCE
1. Open konsole settings -> Keyboard and edit any keytab
2. Put cursor into Test Area Input
3. Press <C-;>

OBSERVED RESULT
Konsole reports `;` was pressed, which makes it impossible to bind <C-;>

EXPECTED RESULT
It should be possible to define keybinding for <C-;>, and other keystrokes with non-alphabetic keys

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Arch Linux
KDE Plasma Version: 5.24.5
KDE Frameworks Version: 5.93.0
Qt Version: 5.15.3