Implement filter checks: ensure all defined filters are used and remove dead code

Integration tests added/updated:
- tests/integration/test_filters_usage.py: AST-based detection of filter definitions (FilterModule.filters), robust Jinja detection ({{ ... }}, {% ... %}, {% filter ... %}), plus Python call tracking; fails if a filter is used only under tests/.
- tests/integration/test_filters_are_defined.py: inverse check — every filter used in .yml/.yaml/.j2/.jinja2/.tmpl must be defined locally. Scans only inside Jinja blocks and ignores pipes inside strings (e.g., lookup('pipe', "... | grep ... | awk ...")) to avoid false positives like trusted_hosts, woff/woff2, etc.

Bug fixes & robustness:
- Build regexes without %-string formatting to avoid ValueError from literal '%' in Jinja tags.
- Strip quoted strings in usage analysis so sed/grep/awk pipes are not miscounted as filters.
- Prevent self-matches in the defining file.

Cleanup / removal of dead code:
- Removed unused filter plugins and related unit tests:
  * filter_plugins/alias_domains_map.py
  * filter_plugins/get_application_id.py
  * filter_plugins/load_configuration.py
  * filter_plugins/safe.py
  * filter_plugins/safe_join.py
  * roles/svc-db-openldap/filter_plugins/build_ldap_nested_group_entries.py
  * roles/sys-ctl-bkp-docker-2-loc/filter_plugins/dict_to_cli_args.py
  * corresponding tests under tests/unit/*
- roles/svc-db-postgres/filter_plugins/split_postgres_connections.py: dropped no-longer-needed list_postgres_roles API; adjusted tests.

Misc:
- sys-stk-front-proxy/defaults/main.yml: clarified valid vhost_flavour values (comma-separated).

Ref: https://chatgpt.com/share/68b56bac-c4f8-800f-aeef-6708dbb44199

tests/unit/roles/svc-db-postgres/filter_plugins/test_split_postgres_connections.py

@@ -77,12 +77,6 @@ class SplitPostgresConnectionsTests(unittest.TestCase):
     def test_registry_contains_filters(self):
         registry = self.mod.FilterModule().filters()
         self.assertIn("split_postgres_connections", registry)
-        self.assertIn("list_postgres_roles", registry)
-
-    def test_list_postgres_roles(self):
-        roles = self.mod.list_postgres_roles(self.roles_dir)
-        self.assertIsInstance(roles, list)
-        self.assertSetEqual(set(roles), {"app_a", "app_b"})
 
     def test_split_postgres_connections_division(self):
         # There are 2 postgres roles -> 200 / 2 = 100

tests/unit/roles/sys-ctl-bkp-docker-2-loc/filter_plugins/test_dict_to_cli_args.py

@@ -1,61 +0,0 @@
-import unittest
-import os
-import sys
-
-# Add the path to roles/sys-ctl-bkp-docker-2-loc/filter_plugins
-CURRENT_DIR = os.path.dirname(__file__)
-FILTER_PLUGIN_DIR = os.path.abspath(
-    os.path.join(CURRENT_DIR, '../../../../../roles/sys-ctl-bkp-docker-2-loc/filter_plugins')
-)
-sys.path.insert(0, FILTER_PLUGIN_DIR)
-
-from dict_to_cli_args import dict_to_cli_args
-
-
-class TestDictToCliArgs(unittest.TestCase):
-    def test_simple_string_args(self):
-        data = {"backup-dir": "/mnt/backups", "version-suffix": "-nightly"}
-        expected = "--backup-dir=/mnt/backups --version-suffix=-nightly"
-        self.assertEqual(dict_to_cli_args(data), expected)
-
-    def test_boolean_true(self):
-        data = {"shutdown": True, "everything": True}
-        expected = "--shutdown --everything"
-        self.assertEqual(dict_to_cli_args(data), expected)
-
-    def test_boolean_false(self):
-        data = {"shutdown": False, "everything": True}
-        expected = "--everything"
-        self.assertEqual(dict_to_cli_args(data), expected)
-
-    def test_list_argument(self):
-        data = {"ignore-volumes": ["redis", "memcached"]}
-        expected = '--ignore-volumes="redis memcached"'
-        self.assertEqual(dict_to_cli_args(data), expected)
-
-    def test_mixed_arguments(self):
-        data = {
-            "backup-dir": "/mnt/backups",
-            "shutdown": True,
-            "ignore-volumes": ["redis", "memcached"]
-        }
-        result = dict_to_cli_args(data)
-        self.assertIn("--backup-dir=/mnt/backups", result)
-        self.assertIn("--shutdown", result)
-        self.assertIn('--ignore-volumes="redis memcached"', result)
-
-    def test_empty_dict(self):
-        self.assertEqual(dict_to_cli_args({}), "")
-
-    def test_none_value(self):
-        data = {"some-value": None, "other": "yes"}
-        expected = "--other=yes"
-        self.assertEqual(dict_to_cli_args(data), expected)
-
-    def test_invalid_type(self):
-        with self.assertRaises(TypeError):
-            dict_to_cli_args(["not", "a", "dict"])
-
-
-if __name__ == "__main__":
-    unittest.main()