[WIP] Adding callsites

[vsoch]

@hainest I've added most of what Jim shared, but Smeagle-ized. This cannot be merged / added until:

1. more discussion from the group around bugs/ implementation. E.g., the inline is a FunctionBase and not a Function and I wonder if the interface could be more consistent.
2. We need to add return types for the new stuff
3. And we need to make the implementation less redundant (I will need your advice on ways to do that).

So I'm tagging WIP for now before we discuss this, and we won't merge obviously until it's added to dyninst proper and I can revert back the original build (Dockerfile, etc.).

[vsoch]

@hainest refactor done to remove inline and try to reduce redundancy of function! I think we probably need to be passing the allocator from the top level function and use reference/pointer to save state but I wasn't sure how to do that (do we need to change the classify template thing?) I might need some pointers for how to do that because what I tried didn't work!

[hainest]

cf. return values at callsite: DW_AT_callsite does not have return type information. Dyninst can produce return type info iff the called function points to an already-parsed function (this is a limitation of the current Dyninst DWARF parser). Can Smeagle check if there is a function declaration that matches the called function in the current CU? If so, we can match params based on that.