path unit: add TriggerLimitBurst= and TriggerLimitIntervalSec=

Given there's now a default for these settings, also allow users to configure
them, matching socket units

src/shared/bus-unit-util.c

@@ -2113,6 +2113,12 @@ static int bus_append_path_property(sd_bus_message *m, const char *field, const
                 return 1;
         }
 
+        if (streq(field, "TriggerLimitBurst"))
+                return bus_append_safe_atou(m, field, eq);
+
+        if (streq(field, "TriggerLimitIntervalSec"))
+                return bus_append_parse_sec_rename(m, field, eq);
+
         return 0;
 }