Add ways to store temporary data

[CTRLRLTY]

Maybe add a new section to define a timed variable that only exist for a specified amount of time. For example:

ingress user {
field:
     name string
}

rule {
...
storage:
     checked bool 10s
     count (string => long) 10s

condition:
     not checked

action:
     checked = true
     count[$user.name] = count[$user.name]  + 1
...
}

The storage section defined two variable checked and count. The content within checked will reset to its default value false after 10 second. The count variable is a map, so it has different mechanism, where each entry will reset relative to its modification.