fix(validate-signature): flag weak timestamp imprints and ignore signer entries

Treat an MD5 or SHA-1 messageImprint as an insecure digest and show the
imprint algorithm in Technical Details.

Ignore Reason, Location, ContactInfo and Name on document timestamps, as
ISO 32000-2 Table 255 requires for ETSI.RFC3161.

The insecure digest status could not be reached because such results are
never valid, so these cards read "Invalid Signature". Show it in the
invalid branch instead.

translations/ui-source.json

@@ -9001,6 +9001,12 @@
     ],
     "fileCount": 1
   },
+  "Timestamp Imprint Algorithm:": {
+    "files": [
+      "logic/validate-signature-pdf-page.ts"
+    ],
+    "fileCount": 1
+  },
   "Timestamp Intact: Timestamp Authority Not Verified": {
     "files": [
       "logic/validate-signature-pdf-page.ts"