dispatch_verify.py loads metrics and specifications from the verify_metrics package by default and add that information to the verification job.

For some verification framework use cases, like in System Verification, metrics and specifications might be defined in different packages. For that, we need a new command line option --metrics-package in dispatch_verify.py to specify the package that hosts metrics and specifications definitions.

If it is not an EUPS package a path to the directory that hosts metrics and specifications definitions also should work.