clean_housenumbers: make kinds and delimiters configurable

Also adds unit tests for various options.

test/python/tokenizer/sanitizers/test_helpers.py

@@ -0,0 +1,43 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# This file is part of Nominatim. (https://nominatim.org)
+#
+# Copyright (C) 2022 by the Nominatim developer community.
+# For a full list of authors see the git log.
+"""
+Tests for sanitizer helper functions.
+"""
+import pytest
+
+from nominatim.errors import UsageError
+import nominatim.tokenizer.sanitizers.helpers as helpers
+
+@pytest.mark.parametrize('inp', ('fg34', 'f\\f', 'morning [glory]', '56.78'))
+def test_create_split_regex_no_params_unsplit(inp):
+    regex = helpers.create_split_regex({})
+
+    assert list(regex.split(inp)) == [inp]
+
+
+@pytest.mark.parametrize('inp,outp', [('here,there', ['here', 'there']),
+                                      ('ying;;yang', ['ying', 'yang']),
+                                      (';a; ;c;d,', ['', 'a', '', 'c', 'd', '']),
+                                      ('1,  3  ,5', ['1', '3', '5'])
+                                     ])
+def test_create_split_regex_no_params_split(inp, outp):
+    regex = helpers.create_split_regex({})
+
+    assert list(regex.split(inp)) == outp
+
+
+@pytest.mark.parametrize('delimiter', ['.', '\\', '[]', '   ', '/.*+'])
+def test_create_split_regex_custom(delimiter):
+    regex = helpers.create_split_regex({'delimiters': delimiter})
+
+    assert list(regex.split(f'out{delimiter}house')) == ['out', 'house']
+    assert list(regex.split('out,house')) == ['out,house']
+
+
+def test_create_split_regex_empty_delimiter():
+    with pytest.raises(UsageError):
+        regex = helpers.create_split_regex({'delimiters': ''})