Use 'shift' keycode instead of numeric code

[ChrisC]

This is a partial fix for a bug that affected the ability to navigate backwards through a document using SHIFT+TAB keys on MacOS.

The ability to navigate backwards using "Single-Key Quick Nav" (which also uses the SHIFT key) is still broken. I would recommend that we merge this partial fix, add some regression testing for our applescript output, and then come back to the Single-Key Quick Nav issue once some more reliable testing is in place for our applescript generators.

[jugglinmike]

Hey @ChrisC! I functionally verified this with the following command:

node aria-at-automation-harness/bin/host.js run-plan \
  --plan-workingdir aria-at/build/tests/horizontal-slider '{reference/**,test-06-*-voiceover_macos.*}' \
  --web-driver-url=http://127.0.0.1:4444 \
  --at-driver-url=ws://127.0.0.1:4382/session \
  --reference-hostname=127.0.0.1 \
  --web-driver-browser=safari > ./harness-run.log

A unit test was failing, so I fixed that. I also added a comment about the key code to make the rationale a little more discoverable than git blame. Let me know if those changes look good to you, and I'll be happy to merge this.

[ChrisC]

Hey @ChrisC! I functionally verified this with the following command:

node aria-at-automation-harness/bin/host.js run-plan \
  --plan-workingdir aria-at/build/tests/horizontal-slider '{reference/**,test-06-*-voiceover_macos.*}' \
  --web-driver-url=http://127.0.0.1:4444 \
  --at-driver-url=ws://127.0.0.1:4382/session \
  --reference-hostname=127.0.0.1 \
  --web-driver-browser=safari > ./harness-run.log

A unit test was failing, so I fixed that. I also added a comment about the key code to make the rationale a little more discoverable than git blame. Let me know if those changes look good to you, and I'll be happy to merge this.

Looks good! Feel free to merge