Introduced ScriptEvaluator strategy interface

Including ScriptEvaluator implementations for JSR-223, Groovy and BeanShell. BeanShell consistently receives the bean ClassLoader now. Also revised ScriptFactory and its implementations for varargs.

Issue: SPR-11007
Polishing
Changed spring-beans-groovy's Groovy dependency to optional

Issue: SPR-11028
Cache InjectionMetadata per bean name instead of per Class

Issue: SPR-11027