WIP: CPP and PY integration

[rogerpearce]

Lets use this checklist to track things needed before merging

• Move python code into py directory.
• Copy clippy-cpp/master into cpp directory. Remove old and dead code
• Fix old examples that have been moved into examples/SimpleExamples. Currently not connected to build system.
• Move tests into examples and rename, e.g. TestBag -> ExampleBag
• Update pytests to use ExampleBag, ExampleSet, etc.
• Integrated pytest at top level of repo? (Decision via msg: in test/ dir at top of repo)
• Add SimpleExamples testing to pytest
• Update top level Readme with current instructions.

Questions?

• Could we have a top level CmakePresets file that would allow developer to build easily from the top level?
• Should we remove files in cpp/tests (they look redundant to top level test now). Later we could add in a cpp/tests if we create self-contained cpp-only tests.

[sbromberger]

Ref: #31

[sbromberger]

my thought: integrated pytest should be in a test directory at the top of the repo.