GUACAMOLE-1291: Add Korean language support

Add translation files for the webapp and the following extensions:

      - guacamole-auth-cas
      - guacamole-auth-duo
      - guacamole-auth-jdbc
      - guacamole-auth-openid
      - guacamole-auth-quickconnect
      - guacamole-auth-saml
      - guacamole-auth-totp

Co-authored-by: hwjdghks <5832120@naver.com>
Co-authored-by: JueunPark <josojoso0702@gmail.com>
Co-authored-by: from97 <skm1104@daum.net>
Co-authored-by: Eomhyunjun <zzp1318@gmail.com>

extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-sqlserver/src/main/resources/guac-manifest.json

@@ -25,6 +25,7 @@
         "translations/es.json",
         "translations/fr.json",
         "translations/ja.json",
+        "translations/ko.json",
         "translations/pt.json",
         "translations/ru.json",
         "translations/zh.json"