- add BaseTracer which will hold most of the boilerplate code
- add hnumpy with a bare NPTracer and tracing function
- update IR to be compatible with tracing helpers
- update test helper to properly check that graphs are equivalent
- add test tracing a simple addition
- rename common/data_types/helpers.py to .../dtypes_helpers.py to avoid
having too many files with the same name
- ignore missing type stubs in the default mypy command
- add a comfort Makefile target to get errors about missing mypy stubs
- value classes have a data_type member to know what they hold
- add __repr__ to a few classes to ease readability for debug/print
- add helper functions to perform value checks that will be used for
tracing to ease readability
- add unit tests to get 100% coverage
