Pytest-testdox

Updates
* Fix DeprecationWarning with hookimpl decorator (96) by nejch
* Drop Python 3.7 support (108)
* Drop Python 3.6 support (87)
* Run tests in PyPy 3.9 (87)
* Ignore tests on PyPy 3.9 on MacOS (105)
* Refactor plugin internal modules (93)
* Setup typechecking (91)
* Run CI tests in Python 3.11 (92)

Development Updates
* Bump codecov/codecov-action from 2.1.0 to 3.1.4 (110)
* Update pytest-cov requirement from ~=3.0.0 to ~=4.1.0 (109)
* Update flake8 requirement from ~=4.0.1 to ~=6.0.0 (95)
* Allow CI workflow to be triggered manually (104)
* Update isort requirement from ~=5.10.0 to ~=5.12.0 (100)
* Bump mypy from 0.982 to 1.4.1
* Bump black from 22.3.0 to 23.3.0
* Bump actions/setup-python from 3 to 4 (78)
* Run tests in Pytest 7+ (88)

* Fix current file path at the tests report when the plugin is in verbose mode (73)
* Update development dependencies (74, 71, 70)

* Drop Python 3.5 support
* Drop Support for Pytest < 4
* Drop Support for PyPy < 3.8
* Add Python 3.10 support
* Add PyPy 3.8 support
* Several refactorings, and code health improvements.

Thanks jairhenrique for the pull requests and code reviews

* Fix missing header when same class name is used in two modules (45)
* Use Python 3.9 at CI/CD (47)

* Drop Python 2 support
* Add "official" support to Pytest 6

Thanks hugovk for the Pull Requests and code reviews.

* Do not require `--testdox` parameter when `--force-testdox` is used
* Register `pytest.mark.describe` and `pytest.mark.it` even when the testdox output is not activated
* Add "official" support to Python 3.8

Thanks spumer for the bug report (31), netolyrg for the bug fix (32) and RomuloOliveira for the usual code review