refactor parts of the dataplane

[jcp19]

Update:

• I will not continue this PR for now. Instead, I will refactor the data plane when we have proper support for access modifiers and ghost fields. Nonetheless, some changes from this PR would be worth merging. Furthermore, we should use the gobra std lib when we introduce a package for maps

Milestones:

• Review usages of map functions everywhere
  • solve completeness problems with the new map encoding
• Modify the mutex predicate of the dataplane to depend on whether the dataplane is running or not - delete TODO in the code
  • maybe put as a parameter of the router whether it is running or not and move the permission of d.running outside of the predicate?
  • Make the spec of all public methods of the dataplane dependent only on public fields (this should be done for the entire codebase eventually)
• simplify svc.go, remove wildcards where possible
• Add triggers everywhere (Review all triggers #101)
• use more pure functions instead of params to predicate (e.g., for localIA)
• Activate conditionalize permissions in this branch
• verify remaining setters
• drop unecessary ghost params in processPkt (most of them can be inferred, from example, from p.rawPkt)