feat(content): Add a separate Gunboat variant for surveillance

[Saugia]

Content (Artwork / Missions / Jobs)

This PR addresses part of what's described in issue #6314

Summary

Currently, the player can encounter Gunboats with scanning equipment in any Navy fleet with a Gunboat present, making it difficult for gameplay such as smuggling when the Navy essentially dogpiles the player whenever a fleet shows up. This PR removes the cargo and outfit scanners from the default Gunboat and adds a specific variant using them, which is placed in the "Navy Surveillance" fleet. Now a smuggler player doesn't necessarily have to fear every single time a Navy fleet shows up.

Surveillance needs a bit more tweaks overall as we feel it is still being over-used, so this PR serves as a start in that direction.

[bene-dictator]

I guess this is partly why the PR is in draft, but the Navy Surveillance fleet doesn't show up until the war begins. A possible solution is adding that fleet to systems from the start of the game, then use one of the deployment events to add the Cruiser and Surveillance Drones to the fleet spawns (they also don't show up until after the war begins). Also don't forget to update the pirate jobs.

Slightly related: thoughts on Free Worlds scanning fleets?

[lumbar527]

thoughts on Free Worlds scanning fleets?

The Free Worlds is a new organization so they likely wouldn't have a lot of scanning equipment. However, because they live in a fairly pirated region, perhaps the Militia could use some surveillance so as to pick up undercover pirates and thus that surveillance could carry over to the Free Worlds.

Just some thoughts.