add driver validations - compare to the driver metadata

[kalsky]

Issue details

When the driver metadata is refering to commands that do not exist in the driver.py, end with a relevant error the pack/install commands of the shellfoundry to prevent issues later on (commands will not be available, etc).

Steps to reproduce

have a few commands in the driver.py and more/different commands in the driver metadata file.
run shellfoundry pack
return errors about missing commands (ones that exist in the metadata and not in the driver.py - the other way is ok)

[GalcQuali]

Hi Yaniv,

Currently we will not implement automatic removal of the commands from the metadata.
However, we will make sure to improve/emphasis this in the dev guide.

Thanks,
Gal.