Localization are not loaded from webjars installed as extensions

Reproduction steps

1. Add an ApplicationResources.properties file in the resource folder of a webjar
2. Install the webjar extension on an instance
3. Try to translate a translation key from the webjar

Expected

The translation key is found.

Actual

The translation key fails to resolve.

Explanations

https://github.com/xwiki/xwiki-platform/blob/master/xwiki-platform-core/xwiki-platform-localization/xwiki-platform-localization-sources/xwiki-platform-localization-source-jar/src/main/java/org/xwiki/localization/jar/internal/JARTranslationBundleFactoryListener.java only check for jar and not webjars or any other supported extensions.
org.xwiki.extension.jar.internal.handler.JarExtensionHandler#isSupported must be used to determine of the resource can be handled as a jar.