Use properties file (resource bundle) for Messages, supporting I18N

[alykhank]

https://docs.oracle.com/javase/tutorial/i18n/ https://www.jetbrains.com/idea/help/internationalization-and-localization-support.html

• [ ] Add src/main/resources/messages.properties and potentially src/main/resources/messages_en_US.properties containing the String constants from Messages.java
• [ ] Use Locale and ResourceBundle in Tailor.java or helper class, to instantiate static ResourceBundle messages and provide convenience functions wrapping messages.getString()