Add option to ignore certain dates in parse_date

PAPERLESS_IGNORE_DATES allows to specify a comma separated list of dates
to ignore during date parsing (from filename and content). This can be
used so specify dates that do appear often in documents but are usually
not the documents creation date (like your date of birth).

src/paperless/settings.py

@@ -4,6 +4,7 @@ import multiprocessing
 import os
 import re
 
+import dateparser
 from dotenv import load_dotenv
 
 from django.utils.translation import gettext_lazy as _
@@ -444,3 +445,10 @@ PAPERLESS_TIKA_ENDPOINT = os.getenv("PAPERLESS_TIKA_ENDPOINT", "http://localhost
 PAPERLESS_TIKA_GOTENBERG_ENDPOINT = os.getenv(
     "PAPERLESS_TIKA_GOTENBERG_ENDPOINT", "http://localhost:3000"
 )
+
+# List dates that should be ignored when trying to parse date from document text
+IGNORE_DATES = set()
+for s in os.getenv("PAPERLESS_IGNORE_DATES", "").split(","):
+    d = dateparser.parse(s)
+    if d:
+        IGNORE_DATES.add(d.date())