fix(lotw): stop reporting suppressed QSOs as uploaded

Reported: ten fresh contacts upload and appear on LoTW; twenty older ones,
bulk-edited to exactly the same LOTW_SENT/RCVD state, are accepted by OpsLog
and never arrive. The operator's reading was that a failed attempt could not be
overridden. It is simpler and worse than that.

TQSL's exit codes, from its own cmdline documentation:

	 8  NO QSOs were processed — already uploaded OR OUT OF DATE RANGE
	 9  some processed, some ignored — same two reasons
	14  some already uploaded, the rest signed

8 and 9 were both read as plain success. So on 8 — nothing uploaded at all —
OpsLog announced "already uploaded (duplicate)" and stamped every selected
contact as sent. They were never on LoTW and now looked as if they were, which
is exactly the reported symptom, and it is not recoverable by re-uploading
because the operator has no reason to try.

"Out of date range" is the cause that bites here: a contact older than the
callsign certificate's validity is silently left out. Older QSOs failing while
today's succeed is the signature.

Now: 8 is a failure and nothing is stamped — a duplicate left at "R" is
harmless and will be refused again, whereas a contact wrongly marked sent is
one nobody will look at twice. 9 and 14 succeed but carry Ignored, and the
caller says so in the console and a toast.

TQSL's own sentence ("20 QSO records are out of date range") is captured and
shown. It was being read and thrown away, and it is the whole answer to "why is
my contact not on LoTW".

internal/extsvc/extsvc.go

@@ -142,4 +142,10 @@ type UploadResult struct {
 	OK      bool   // the service accepted (or already had) the QSO
 	LogID   string // service-assigned record id, when provided
 	Message string // human-readable detail (reason on failure)
+	// Ignored is set when the service accepted the submission but left some or
+	// all of the QSOs out of it. TQSL does this for contacts already uploaded
+	// AND for contacts outside the certificate's date range, and reports both
+	// with the same exit code — so the caller must show the message rather than
+	// decide on its own that everything went through.
+	Ignored bool
 }