add support for dependency introspection at runtime

[monperrus]

Functional requirements: Classport.getDependencyInfo() can be called anywhere, and returns where we are in the dependency tree

Non-Functional requirements: This goes fast, say < 10% overhead.

[algomaster99]

jstack is a command-line utility which could print stack trace for a running JVM. @serenacofano could you give this a try and see if we could also retrieve class file bytes? Once we have bytes we can also extract the annotation from it.