Nerf the Sera T3 Subhunter and make larger formations of it less oppressive

[Basilisk3]

Description of the proposed changes

Main armament
Damage: 290 --> 380
RateOfFire: 0.25 --> 0.22
MuzzleSalvoDelay: 0.7 --> 1
MuzzleSalvoSize: 5 --> 4
DPS: 363 --> 338

Torpedo Defenses
RateOfFire: 0.15 --> 0.1

Results of the changes

• Destroyers and Torpedo Boats are more effective against the Yathsou
• Torpedo Defenses cannot be overwhelmed as quickly as before
• Torpedo Bombers are more effective
• Ground-firing remains unchanged

For further explantions see #5894 (Closes #5894)

Checklist

• Changes are documented in the changelog for the next game version (in separate PR)

[zqh9843]

The nerf was a bit too much imho tbh. Also considering Sera's lack of mass efficient T2 sub killer, I think nerfing the damage to 270 so it's closer to the pre-change stats(about 337.5) is way better than overdoing it.

[Basilisk3]

I understand your concerns, please see my comment in #5894 for further context and an explanation as to why this is necessary.