feat: Include numeric key code in KeyEvent Debug

[thomasa88]

Describe your changes. Use imperative present tense.

Add the numeric key code value after the enum literal name in debug prints of KeyEvent.

Printing the numeric key code together with the pressed key enum value makes it much easier to create custom deflocalkeys.

Example --debug output:

21:42:09.5202 [DEBUG] (3) kanata_state_machine::kanata: process recv ev KeyEvent { code: KEY_LEFTCTRL (29), value: Press }
21:42:09.6403 [DEBUG] (3) kanata_state_machine::kanata: process recv ev KeyEvent { code: KEY_I (23), value: Press }

Checklist

• Add documentation to docs/config.adoc
  • N/A
• Add example and basic docs to cfg_samples/kanata.kbd
  • Yes, short info.
• Update error messages
  • N/A
• Added tests, or did manual testing
  • Yes, tested on Linux

It might be a better fit to modify the Debug implementation of OsCode, but I'm not sure how to do it correctly.

[jtroo]

Thanks for the PR!