Fix quoting in keyboard matching

[tarasglek]

Describe your changes. Use imperative present tense.

Strip surrounding syntax quotes from definputdevices matcher values before matching or parsing them.

Without this fix, I could not match an external keyboard on my Mac using the documented quoted name syntax: the parser retained the literal quote characters. Quoted hash values also failed hexadecimal validation.

Reuse trim_atom_quotes() and add a regression test covering quoted names, vendor/product IDs, and an uppercase quoted hash.

Checklist

• Add documentation to docs/config.adoc
  • N/A — existing documentation already specifies quoted matcher values
• Add example and basic docs to cfg_samples/kanata.kbd
  • N/A — this fixes existing syntax rather than adding a new configuration feature
• Update error messages
  • N/A
• Added tests, or did manual testing
  • Yes

[jtroo]

Thanks!