Add logging entry indicating that script execution is completed

I would like to be able to tell from logs when exactly the APM script was being executed.
Currently, only start of execution is reported with:
https://github.com/wttech/APM/blob/master/app/aem/core/src/main/java/com/cognifide/apm/core/scripts/ScriptManagerImpl.java#L116C5-L116C81

It would be great to see when it finishes with some summary like: status (success vs. fail, execution time, etc).