Tidy ups + unit tests:

1. Allow loading modules from --module_paths=/extra/path/here
2. Improved unit tests for module loading
3. Further small tidy ups/clean ups

src/auto_archiver/modules/hash_enricher/hash_enricher.py

@@ -19,16 +19,6 @@ class HashEnricher(Enricher):
     Calculates hashes for Media instances
     """
 
-    def __init__(self, config: dict = None):
-        """
-        Initialize the HashEnricher with a configuration dictionary.
-        """
-        super().__init__()
-        # TODO set these from the manifest?
-        # Set default values
-        self.algorithm = config.get("algorithm", "SHA-256") if config else "SHA-256"
-        self.chunksize = config.get("chunksize", int(1.6e7)) if config else int(1.6e7)
-
 
     def enrich(self, to_enrich: Metadata) -> None:
         url = to_enrich.get_url()

src/auto_archiver/modules/html_formatter/html_formatter.py

@@ -12,7 +12,7 @@ from auto_archiver.core import Metadata, Media, ArchivingContext
 from auto_archiver.core import Formatter
 from auto_archiver.modules.hash_enricher import HashEnricher
 from auto_archiver.utils.misc import random_str
-
+from auto_archiver.core.module import get_module
 
 @dataclass
 class HtmlFormatter(Formatter):
@@ -53,7 +53,7 @@ class HtmlFormatter(Formatter):
             outf.write(content)
         final_media = Media(filename=html_path, _mimetype="text/html")
 
-        he = HashEnricher({"hash_enricher": {"algorithm": ArchivingContext.get("hash_enricher.algorithm"), "chunksize": 1.6e7}})
+        he = get_module('hash_enricher', self.config)
         if len(hd := he.calculate_hash(final_media.filename)):
             final_media.set("hash", f"{he.algorithm}:{hd}")