[KBM]Set extended flag for media keys

[jaimecbernardo]

Summary of the Pull Request

Keyboard manager is sending scancodes for media keys which are being interpreted in some applications as other keys, as is exemplified in the issue this PR closes ( #25463 ).
This is caused by us sending the scancode without prefixing it with e0 as expected for extended keys (which in key events means adding the KEYEVENTF_EXTENDEDKEY flag to the event).
This PR adds the Windows Multimedia keys to the list of keys we're sending the extended flag. Source used to select the keys is: https://tigerheli.mameworld.info/encoder/scancodesset2.htm

PR Checklist

• Closes: Keyboard Manager Mapping Issue with Audiovoicedown Key #25463
• Communication: I've discussed this with core contributors already. If work hasn't been agreed, this work might be rejected
• Tests: Added/updated and all pass
• Localization: All end user facing strings can be localized
• Dev docs: Added/updated
• New binaries: Added on the required places
  • JSON for signing for new binaries
  • WXS for installer for new binaries and localization folder
  • YML for CI pipeline for new test projects
  • YML for signed pipeline
• Documentation updated: If checked, please file a pull request on our docs repo and link it here: #xxx

Validation Steps Performed

As mentioned in the issue, used https://en.key-test.ru/ to verify that, without the fix, mapping a key to Volume Down was registering the key C as well.
With the fix, using a key mapped to volume down no longer registers C.