Up until #4999 we deferred all key events to the character event handler
for which `ToUnicodeEx` returned a valid character and alternatively
those who aren't a special key combination as listed in
`TerminalInput`'s implementation.
Since #4999 we started acknowledging/handling all key events no matter
whether they're actually a known key combination. Given non-ASCII inputs
the Win32 `SendInput()` method generates certain sequences that aren't
recognizable combinations though and if they're handled by the key event
handler no follow up character event is sent containing the unicode
character.
This PR adds another condition and defers all key events without scan
code (i.e. those not representable by the current keyboard layout) to
the character event handler.
I'm absolutely not certain that this PR doesn't have a negative effect
on other kinds of inputs.
Is it common for key events to not contain a scan code? I personally
haven't seen it happen before AutoHotKey/SendInput.
Before this PR is merged it'd be nice to have a good testing plan in
place in order to ensure nothing breaks.
## Validation Steps Performed
Remapped `AltGr+8` to `»` using AutoHotKey using `<^>!8::SendInput {Raw}»`.
Ensured `»` is printed if `AltGr+8` is pressed.
Closes#7064Closes#7120