Added the sonar pulse to reveal sub marines

As described in #4729 this was never implemented. Balancing wise I decided to make this a localized but multi-shot event similar to the spy plane. A good test case is http://resource.openra.net/maps/495/ which has creeps with an infiltratable sub pen and a submarine next to it plus soldiers that can be used as a disguise against the pillboxes.
Better to write an upgrade rule now when it is just a simple trait rename, vs later after mappers have discovered that they can use this trait for e.g. spy satellites, spawning resource fields, custom weapon detonations (via an actor with a death weapon), etc.

`SonarPing` could be named more generically as `DeploySound`.