feat(character-gallery): 이미지 구매 기능 추가

SodaLive/Sources/Chat/Character/Detail/Gallery/CharacterDetailGalleryRepository.swift

@@ -40,4 +40,8 @@ final class CharacterDetailGalleryRepository {
             )
         )
     }
+    
+    func purchaseCharacterImage(imageId: Int) -> AnyPublisher<Response, MoyaError> {
+        return characterApi.requestPublisher(.purchaseCharacterImage(imageId: imageId))
+    }
 }