[keycloak-dev] keycloak.js and iframe caching issues

When keycloak.js and the session iframe are updated that can cause issues as they are currently cached by the browser. This is now changed and unless keycloak.js is loaded with ?version=<KC VERSION> they will no longer be cached. If you load keycloak.js with ?version<KC VERSION> it will automatically load the iframe with the same query param which makes that cached as well.