util-lib: split string parsing related calls from util.[ch] into parse-util.[ch]

src/basic/signal-util.c

@@ -19,11 +19,11 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#include "parse-util.h"
+#include "signal-util.h"
 #include "string-util.h"
 #include "util.h"
 
-#include "signal-util.h"
-
 int reset_all_signal_handlers(void) {
         static const struct sigaction sa = {
                 .sa_handler = SIG_DFL,
@@ -268,3 +268,7 @@ int signal_from_string_try_harder(const char *s) {
 
         return signo;
 }
+
+void nop_signal_handler(int sig) {
+        /* nothing here */
+}