`keybindings` of dead keys using AltGr+X

@lhecker is already working on this.

Since May 27, 2021.

### Windows Terminal version (or Windows build number)

1.9.1445.0

### Steps to reproduce

- Use a keyboard that has a dead key hidden behind a altgr+X combo. (This is the case for instance on AZERTY keyboards for the \~ or the \` keys: the former is a dead key that requires altGr+\~ or ctrl+alt+\~ (the \~ is located on the 2 key, the \` on the 7 key))

The AZERTY keyboard for context:

- Bind that dead key to some action. for instance, I use those two `keybindings` to "un-deadify" some keys:
```json
{
"command": {
"action": "sendInput",
"input": "^"
},
"keys": "^"
},
{
"command": {
"action": "sendInput",
"input": "~"
},
"keys": "ctrl+alt+~"
}
```

### Actual Behavior

Both ^ and ~ keys are dead keys.

- If I type ^, it works great: the `^` shows up instantly and doesn't act as a dead key.
- If try to print a `~` it does work great when doing ctrl+alt+\~ (what `altgr` is an alias of), but not when using altGr+\~:
- when doing ctrl+alt+\~: the key shows instantly
- when doing altGr+\~: the key still acts dead (I need to add a space for `~` to show up)
- I made sure that `altGrAliasing` was turned on.

### Comments

This issue follows my previous https://github.com/microsoft/terminal/issues/5784 issue. TBF, this is the edge case of an edge case, and I would understand if this never got fixed... I'm just secretly hoping for another `@lhecker` miracle 😄 but can probably live without it