bug(web): macOS-Chrome chiral key behavior

This bug was discovered during testing of #6808 with the "Development Chirality Test Keyboard" found at `web/testing/chirality`.

# Test Results

All tests done on iPad mini 6 running iOS 15.5.

* **TEST_CHIRALITY_HARDWARE (FAILED):**
In Chrome on macOS 12.4, the keycaps shown don't correspond with keys triggered and fired on the hardware keyboard.

Type keys ertyu while holding LAlt on the hardware keyboard, output `´®ʈɥ¨` instead of the expected `ɛɽʈɥʊ`. See the comparison below.

| With | Keys | actual output| screenshot of actual output | expected output |
| --- | --- | --- | --- | --- |
| OSK | LAlt + ertyu | `ɛɽʈɥʊ ` | | `ɛɽʈɥʊ` |
| Hardware | LAlt + ertyu | `´®ʈɥ¨` | | `ɛɽʈɥʊ` |

In Chrome on Windows 10 Pro 21H2, the keycaps shown do correspond with keys triggered and fired on the hardware keyboard.

Failed this test for now as it doesn't work on macOS.

_Originally posted by @MakaraSok in https://github.com/keymanapp/keyman/issues/6808#issuecomment-1169689188_

Interestingly, the issue doesn't reproduce if you use Chrome on macOS to simulate an iPad; you need to be testing against macOS itself, not Android or iOS.