[git] Refactor script (#227)

Make the script more readable, mostly by:

- using the Product and AutoConfig classes,
- removing the use of functions when unnecessary,
- a little bit of renaming and documentation.

Note that this also changed the module used for regexes in endoflife.py. The regex module is now used because the Python re module does not support identically named groups (as used in the mariadb product). The regex module being backwards-compatible with the standard re module, this should not be an issue.

src/common/endoflife.py

@@ -2,7 +2,7 @@ import frontmatter
 import json
 import logging
 import os
-import re
+import regex as re  # Python re module does not support identically named groups (as used in the mariadb product)
 from datetime import datetime
 from glob import glob
 from liquid import Template