Broadcast signals with higher priority

[Enchufa2]

Otherwise, an arrival may catch its own signal with a trap after send. Test case needed.

[Enchufa2]

We have:

library(simmer)

t <- trajectory() %>%
  send("signal") %>%
  trap("signal") %>%
  timeout(1)

simmer() %>%
  add_generator("dummy", t, at(0, 0)) %>%
  run() %>%
  get_mon_arrivals()
#>     name start_time end_time activity_time finished replication
#> 1 dummy0          0        0             0     TRUE           1
#> 2 dummy1          0        0             0     TRUE           1