Ability to provide path to get the ops files from

[mathewparet]

This enhancement provides an extra parameter to the operations:show and operations:process commands to allow user to specify the path the operations files can be loaded from.

[mathewparet]

That's all the commits. I'm sorry for the mess of submitting multiple commits to this pull request after it was originally raised. This is the first time I'm working on a pull request. I've tested all possible scenarios I could think off and it works fine now.

Enhancements so far:

1. Added --path option to operations:show and operations:process so that you can load operations from a custom path.
2. Added --database option to operations:process so that you can specify the database connection against which the operations should be run.

[mathewparet]

Support for --job flag so that the process job class can be overridden while running operations:process command. This is useful, say in case you wish to implement operations for a multi-tenancy setup using spatie/laravel-multitenancy. Most multi-tenancy packages require you to implement a special interface for jobs so that they can be tagged as a tenant job. This change provides support for that so that the developer can extend the OneTimeOperationProcessJob job and add a the required implementation of the TenantAware (or similar) interface so that the jobs run in tenancy.