We are renaming files in the pythonic API to make it look less like it is somehow part of z3 (but still acknowledge that we took code from z3Py properly). This PR follows the change in cvc5/cvc5_pythonic_api#80.
We decided we want to ship the pythonic API together with our base python API.
This PR adds a new target cvc5_python_api that first builds the base python API and then copies the pythonic API over. Furthermore we now use the cvc5.pythonic module to generate the corresponding documentation.
