Display Warship count (#756)

## Description:
Missile launchers:
SAMs:
And now Warships:

## Please complete the following:

- [x] I have added screenshots for all UI updates
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced
- [x] I understand that submitting code with bugs that could have been
caught through manual testing blocks releases and new features for all
contributors

## Please put your Discord username so you can be contacted if a bug or
regression is found:

<DISCORD USERNAME>
dovg

resources/lang/en.json

@@ -365,6 +365,7 @@
     "cities": "Cities",
     "missile_launchers": "Missile launchers",
     "sams": "SAMs",
+    "warships": "Warships",
     "health": "Health",
     "attitude": "Attitude"
   },

src/client/graphics/layers/PlayerInfoOverlay.ts

@@ -264,6 +264,10 @@ export class PlayerInfoOverlay extends LitElement implements Layer {
           ${translateText("player_info_overlay.sams")}:
           ${player.units(UnitType.SAMLauncher).length}
         </div>
+        <div class="text-sm opacity-80" translate="no">
+          ${translateText("player_info_overlay.warships")}:
+          ${player.units(UnitType.Warship).length}
+        </div>
         ${relationHtml}
       </div>
     `;