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

src/bootchart/bootchart.c

@@ -55,6 +55,7 @@
 #include "io-util.h"
 #include "list.h"
 #include "macro.h"
+#include "parse-util.h"
 #include "path-util.h"
 #include "store.h"
 #include "string-util.h"

src/bootchart/store.c

@@ -35,6 +35,7 @@
 #include "cgroup-util.h"
 #include "fd-util.h"
 #include "fileio.h"
+#include "parse-util.h"
 #include "store.h"
 #include "string-util.h"
 #include "strxcpyx.h"