Fix blank SMTP TLS failure-detail fields crashing saves; read RFC 8460 additional-information (11.0.3) (#916)

* Treat blank SMTP TLS failure-detail fields as absent; read RFC 8460 additional-information

Some reporters send optional failure-details fields as empty strings
(e.g. "sending-mta-ip": "" on sts-policy-fetch-error). The parser copied
them verbatim, so the PostgreSQL save failed on the INET columns
("invalid input syntax for type inet") and the Elasticsearch/OpenSearch
saves failed Ip() validation, discarding the whole report. Blank or
whitespace-only optional values are now omitted.

RFC 8460 section 4.4 names the URI key "additional-information"; the
parser only read "additional-info-uri" (the schema's value placeholder),
so conformant reports lost the URI. The RFC key is now read, with the old
key kept as a fallback.

Bump version to 11.0.3.

Closes #915

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

* Import parse_report_file directly in the ES/OpenSearch tests

Addresses github-code-quality's "Module is imported with 'import' and
'import from'" findings on tests/test_elastic.py and
tests/test_opensearch.py.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

samples/smtp_tls/empty_failure_detail_fields.json

@@ -0,0 +1,38 @@
+{
+    "organization-name":"Reporter Example",
+    "date-range":{
+       "start-datetime":"2024-06-01T00:00:00Z",
+       "end-datetime":"2024-06-01T23:59:59Z"
+    },
+    "contact-info":"smtp-tls-reporting@reporter.example",
+    "report-id":"2024-06-01T00:00:00Z_example.com",
+    "policies":[
+       {
+          "policy":{
+             "policy-type":"sts",
+             "policy-string":[
+                "version: STSv1",
+                "mode: enforce",
+                "mx: example.com",
+                "max_age: 86400"
+             ],
+             "policy-domain":"example.com"
+          },
+          "summary":{
+             "total-successful-session-count":0,
+             "total-failure-session-count":1
+          },
+          "failure-details":[
+             {
+                "result-type":"sts-policy-fetch-error",
+                "sending-mta-ip":"",
+                "receiving-ip":"",
+                "receiving-mx-hostname":"",
+                "failed-session-count":1,
+                "additional-information":"",
+                "failure-reason-code":"no-policy-served"
+             }
+          ]
+       }
+    ]
+}