Proposal: Extend Role to include Hierarchical role

[visto9259]

The current implementation of Role only support flat roles.
Hierarchical roles is implemented by HierarchicalRole.
InMemoryRoleProvider and ObjectRepositoryRoleProvider use hierarchical roles.
Laminas' role is a hierarchical role.

Therefore, hierarchical role should be the "default". Flat role is just a hierachical role with no children.

Proposal:

• Have Role support hierarchical role which makes it more like Laminas'
• Extend RoleInterface to include hasChildren and getChildren
• Have HierarchicalRole extend Role and mark it as deprecated
• Have HierarchicalRoleInterface extend RoleInterface and mark it as deprecated.

[visto9259]

Completed