Implement rule reload mechanism

[jptosso]

Maybe we could replace waf.Rules pointer in runtime without affecting the users but I'm not sure if it might panic in some cases

Other mechanism would be to remove waf.Rules and replace it with:

func (w *Waf) Rules() *RuleGroup {
  w.rgMux.RLock()
  defer w.rgMux.RUnlock()
  return w.rules
}

That way we could lock .Rules() whenever we are refreshing the rules with something like wwaf.SetRules(someRuleGroup).

[github-actions]

This issue is stale because it has been open for 30 days with no activity.

[syinwu]

This is still happening.

[jptosso]

Maybe this problem should be solved by the connectors and not by Coraza ?