evaluator rules: Add an approval mechanism for a couple of rules

[fviernau]

All rules which state "This requires approval." in their error message are candidates for
extension with an approval mechanism.

The mechanism could cover the following ways:

1. For (license, package) disregarding product context.
2. For (license, project) disregarding package context.
3. For license globally, disregarding product and package context.
4. For (licence, package, project)

In a future iteration it could be reasonable to think about adding optional expiration dates to approvals.
Use case: If an org has a contract which allows the use only for a certain time frame, the approval must be revisited later on.