Func-adl-xaod

These changes and fixes came from our stress test running on the CMS Run 1 AOD Data for the Higgs Rediscovery

* Added more CMS AOD Type info (far from complete!)
* Upgrade to modern version of awkward for behind-the-scenes work
* Now possible to do null checks - isNonNull from CMS, specifically. Implemented as an add-on function, not something that is central to the design of the code generator, unfortunately.
* One can now extract member variables of C++ structs and classes
* If the top level `Select` statement is resolves to a dictionary, then a ROOT file with columns the names of the dictionary items will be written out automatically (no need for AsROOT or etc.). This brings it in line with `uproot`'s transformer support.
* Much like `tuple` resolution, one now has inline `dict` resolution. This should make it much easier to build new data models on the fly if need be.
* Fixed a bug in scoping of representations, which should make deeply nested statement translation (more) robust.
* Added the "**" python operator (`pow` in C++)
* Technical debt, some of it at least, repaied.
* Improvements to test coverage

Make sure the output file directory goes in the right place for CMS

* Enable inline dict resolution, like what existed already in the uproot backend
* Fix bug in the return type for functions
* Fix bug in scoping of previously resolved representations
* Added a few new types and collections
* Added ability to tell the difference between an object that is a pointer, and is a flat out object (particularly useful for Handle like objects in CMS).

This is a very minor bug-fix release.

* `isNotnull`, which is on a `Ref` object rather than its pointer, has been added so one can check for null's.
* Add header files for complete Muon access, and types to be able to access the C++ objects in the edm for this demo analysis.
* Big clean up of flake8 errors in the tests directory
* Testing moves to a modern version of awkward.

This can now be used to process CMS Run 1 AOD's as well as Atlas R20 xAOD's

* Code has been significantly refactored
* Added the `Range` operator to iterate over a sequence of numbers
* Support CMS Run 1 AOD's

CMS writes its tree down a level