Refactor scripts arguments handling (#456)

- remove the use of environment variables to get directory paths,
- make use of arguments / argparse instead of environment variables in `update.py` and `report.py`,
- automatically guess the data directory in `latest.py` based on the script's location,
- propagate log level to auto scripts,
- move `list_configs_from_argv` from `endoflife` module to `releasedata` module,
- use `list_products` in `latest.py` to load the product's frontmatters.

src/release_table.py

@@ -150,7 +150,7 @@ class Field:
         return f"{self.name}({self.column})"
 
 
-for config in endoflife.list_configs_from_argv():
+for config in releasedata.list_configs_from_argv():
     with releasedata.ProductData(config.product) as product_data:
         render_javascript = config.data.get("render_javascript", False)
         render_javascript_click_selector = config.data.get("render_javascript_click_selector", None)