build: subpackages implementation (#164)

* migrate to hatch

* reorder tests

* generic fixtures

* straight forward conftest

* fix docs generation

* fix tox environments

* reformat tomls

* cleanup pyproject

* some play with renaming

* move root conftest into pytest plugins

* fix setup script

* move fixtures to __init__.py

* remove duplicate fixtures

* disable pylint warning

* simplify configuration fixture

* remove empty conftest

* remove crap from local pyprojects

.pytest.toml

@@ -0,0 +1,8 @@
+[pytest]
+addopts = [
+    "--spec",
+]
+asyncio_default_fixture_loop_scope = "function"
+asyncio_mode = "auto"
+"resource-path.directory-name-test-resources" = "../../tests/testresources"
+spec_test_format = "{result} {docstring_summary}"