Enhance: missile silo shows SAM previews (#2578)

## Description:

Missile silos should also show SAM previews for placement consideration.

## Please complete the following:

- [X] I have added screenshots for all UI updates
- [X] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [X] I have added relevant tests to the test directory
- [X] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced

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

bibizu

src/client/graphics/layers/SAMRadiusLayer.ts

@@ -107,8 +107,9 @@ export class SAMRadiusLayer implements Layer {
       }
     }
 
-    // show when in ghost mode for sam/atom/hydrogen
+    // show when in ghost mode for silo/sam/atom/hydrogen
     this.ghostShow =
+      this.uiState.ghostStructure === UnitType.MissileSilo ||
       this.uiState.ghostStructure === UnitType.SAMLauncher ||
       this.uiState.ghostStructure === UnitType.AtomBomb ||
       this.uiState.ghostStructure === UnitType.HydrogenBomb;