Implement alert instruction whitespace normalization

internal/forecast/derive.go

@@ -492,7 +492,7 @@ func parseAlert(raw json.RawMessage) (parsedAlert, bool) {
 		Headline:    firstStringField(fields, "headline", "title"),
 		Severity:    stringField(fields, "severity"),
 		Description: stringField(fields, "description"),
-		Instruction: stringField(fields, "instruction"),
+		Instruction: collapseWhitespace(stringField(fields, "instruction")),
 	}
 	start, startOK := firstTimeField(fields, "onset", "startsAt", "startTime", "effective", "sent")
 	end, endOK := firstTimeField(fields, "ends", "endsAt", "endTime", "expires")
@@ -542,6 +542,10 @@ func firstTimeField(fields map[string]json.RawMessage, names ...string) (time.Ti
 	return time.Time{}, false
 }
 
+func collapseWhitespace(value string) string {
+	return strings.Join(strings.Fields(value), " ")
+}
+
 func intersect(left timeutil.Period, right timeutil.Period) timeutil.Period {
 	start := left.Start
 	if right.Start.After(start) {