Fixes #7140 - product opt missing from cv add repo

This makes product option available in content-view add-repository and
remove-repository commands.
product option was missing from content-view add-repository and
remove-repository so the user was unable to add/remove repositories
since respository is scoped to a product.
Merge pull request #225 from dustint-rh/cv_add_repo_missing_product_opt

Fixes #7140 - product opt missing from cv add repo