Fix keyboard shortcuts to fully work with more layouts than QWERTY

### Steps to reproduce

I'm using Linux with a German QWERTZ layout in hardware and software. I tried all shortcuts the menu presented me with on my platform and in this order.

1. Ctrl+/ does not work on QWERTZ https://github.com/vector-im/element-web/issues/21049#issuecomment-1039028343
2. Ctrl+> does not work on QWERTZ as > is produced by Shift+<
3. Ctrl+Shift+U does not work and starts [unicode composition](https://help.ubuntu.com/community/ComposeKey#Unicode_composition) instead, see also https://github.com/vector-im/element-web/issues/3232#issuecomment-904474898
4. `Clear room list filter field` does not apply anymore with new spotlight #21068
5. Ctrl+` does not work on QWERTZ #19694 and is likely a deadkey and breaks macOS #14381
6. Ctrl+; as introduced by https://github.com/matrix-org/matrix-react-sdk/pull/7985 does not work

Most of these do not work because while they are basic keys on QWERTY, they require combinations on different layouts. For example / is present on QWERTY with a single keypress, but on QWERTZ it requires Shift+7 to type it.

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### Untested

- Ctrl+Alt+Up/Down idk it just does nothing but maybe testing wrong
- Ctrl+D
- Ctrl+E

### Outcome

#### What did you expect?
these work

#### What happened instead?
do not work. I am certain that with more international layouts, more issues arise.

## Related
- I think these could technically be worked around if they were customizable #15076
- To retain mnemonics (i.e. position of keys with related left-right functions are next to each other #21049)

### Operating system

arch

### Application version

Element Nightly version: 2022021401 Olm version: 3.2.8

### How did you install the app?

aur

### Homeserver

1.52

### Will you send logs?

No