renamed 'localized-composite' module to 'localizedComposite' conform naming conventions of all other tests
renamed 'LocalizedComposite' in filenames to 'Issue5160' conform naming conventions of all other tests
extract UIViewRoot locale from Accept-Language header instead of request.getLocale() because the latter apparently drops unsupported variants depending on currently used JDK, unintentionally causing the IT to fail
Replaces https://github.com/jakartaee/faces/pull/1721 and fixes https://github.com/eclipse-ee4j/mojarra/issues/5160
Changes as compared to #1721: