feat(templates): add helper functions for metadata editor form rendering

Add textToString, tagSliceToString, stringSliceToString, and
formatDateForInput to convert pgtype/[]string values into HTML input
value attributes for the metadata editor form fields.

templates/utils.go

@@ -220,3 +220,25 @@ func FormatTimestamptzInTimezone(t pgtype.Timestamptz, timezone string) string {
 	}
 	return FormatInTimezone(t.Time, timezone)
 }
+
+func textToString(t pgtype.Text) string {
+	if t.Valid {
+		return t.String
+	}
+	return ""
+}
+
+func tagSliceToString(tags []string) string {
+	return strings.Join(tags, ", ")
+}
+
+func stringSliceToString(s []string) string {
+	return strings.Join(s, ", ")
+}
+
+func formatDateForInput(d pgtype.Date) string {
+	if !d.Valid {
+		return ""
+	}
+	return d.Time.Format("2006-01-02")
+}