Refactor packaging, part I

Relates to #75 (closed).

Move all project info to pyproject.toml.

Tasks:

• Static Project Info
• Register and run versioneer
• Register Cython extension modules
• Clean up package data files & manifest
• Remove quicktest action from setup.py and realize quicktests some other way -> introduced quicktest.py

Notes:

• The quicktest command in setup.py uses the distutils command interface, but distutils is deprecated since Python 3.10. We must find some other way to realize quicktests.

pyproject.toml

@@ -12,13 +12,7 @@ authors = [
 ]
 license = { file = "COPYING.txt" }
 requires-python = ">=3.10"
-dependencies = [
-    "sympy>=1.6,<=1.11.1",
-    "numpy>=1.8.0",
-    "pymbolic>=2022.2",
-    "appdirs",
-    "joblib",
-]
+dependencies = ["sympy>=1.6,<=1.11.1", "numpy>=1.8.0", "appdirs", "joblib"]
 classifiers = [
     "Development Status :: 4 - Beta",
     "Framework :: Jupyter",