sleep-util: split battery-capacity into sleep/

This is only used by sleep.c. Let's start shrinking down
the "mixed" sleep-util.

src/test/test-sleep.c

@@ -117,33 +117,6 @@ TEST(sleep) {
         log_info("Suspend-then-Hibernate configured and possible: %s", r >= 0 ? yes_no(r) : STRERROR(r));
 }
 
-TEST(fetch_batteries_capacity_by_name) {
-        _cleanup_hashmap_free_ Hashmap *capacity = NULL;
-        int r;
-
-        assert_se(fetch_batteries_capacity_by_name(&capacity) >= 0);
-        log_debug("fetch_batteries_capacity_by_name: %u entries", hashmap_size(capacity));
-
-        const char *name;
-        void *cap;
-        HASHMAP_FOREACH_KEY(cap, name, capacity) {
-                assert(cap);  /* Anything non-null is fine. */
-                log_info("Battery %s: capacity = %i", name, get_capacity_by_name(capacity, name));
-        }
-
-        for (int i = 0; i < 2; i++) {
-                usec_t interval;
-
-                if (i > 0)
-                        sleep(1);
-
-                r = get_total_suspend_interval(capacity, &interval);
-                assert_se(r >= 0 || r == -ENOENT);
-                log_info("%d: get_total_suspend_interval: %s", i,
-                         r < 0 ? STRERROR(r) : FORMAT_TIMESPAN(interval, USEC_PER_SEC));
-        }
-}
-
 static int intro(void) {
         if (getuid() != 0)
                 log_warning("This program is unlikely to work for unprivileged users");