Deprecate InstanceGraph (#1800)

* InstanceKeyGraph: add staticInstanceCount, getGraph and getChildrenInstanceMap

* InstanceKeyGraph: reachableModules, unreachableModules, lowestCommonAncestor and fullHierarchy

* Replace usage of InstanceGraph with InstanceKeyGraph

Also deprecates all unused methods.

* WiringUtils: make new version of sinksToSources package private

This will make our live easier next time we need to change it.

* CircuitGraph: use InstanceKeyGraph

* InstanceKeyGraphSpec: respect maximum line width

* InstanceKeyGraph: make constructor private

* InstanceKeyGraph: move lowestCommonAncestor function to Wiring

* WiringUtils: update deprecation message