feat(semester-process-volunteer): add controller, routes, policies and basic scaffold for views to the model

evaluation done in ApplicationPolicy

- we don't repeat ourselves anymore
  - define a rule once, and apply it to the desired actions
- its a "list" of actions, that get rule with explicit name applyed
  - In my view, this is just so much better to oversee what which actions gets
- the policy classes are much slimmer
  - so the policys for one controller can mostly seen on one screen