Set job name as metadata when pulled from SM

When the job is pulled from the job plugin manager, set its name
so it can be used to instantiate that job again by its service
name.

This should actually be combined with [this change](https://github.com/juriansluiman/SlmQueue/commit/0d10cb092e4740ff78445850428b7b185be85772#diff-82d9e24a08d88df3693611fda3481851R91) from a previous PR. 

The "problem" I have here is that the name is set in another place than consumption happens. The job interface itself does not know anything about a name. @bakura10 should we add a `JobInterface#setName($name)` method or keep it like this?

This PR solves #85 
validatePlugin