Refactor: Migrate network layer from Retrofit to Ktor

This commit migrates the network layer from Retrofit to Ktor.

Specific changes include:

-
 Replaced Retrofit with Ktor for network requests.
- Updated dependencies to include Ktor libraries.
- Refactored network service and data classes to use Ktor's API.
- Removed Retrofit-specific code and dependencies.
- Adjusted network module to provide Ktor client and services.
- Updated Pixabay
ImageRepository to use the new Ktor-based PixabayService.
- Introduced Result sealed class to handle network responses.
- Updated PhotoDetailViewModel to handle Result.Error state.

feature/details/src/main/kotlin/dev/adriankuta/pixabay/feature/details/PhotoDetailViewModel.kt

@@ -5,6 +5,7 @@ import androidx.lifecycle.viewModelScope
 import dagger.assisted.Assisted
 import dagger.assisted.AssistedInject
 import dagger.hilt.android.lifecycle.HiltViewModel
+import dev.adriankuta.pixabay.data.Result
 import dev.adriankuta.pixabay.data.repository.ImageRepository
 import dev.adriankuta.pixabay.feature.details.di.PhotoDetailsViewModelFactory
 import kotlinx.coroutines.flow.SharingStarted
@@ -23,7 +24,12 @@ class PhotoDetailViewModel @AssistedInject constructor(
     }
 
     val uiState = loadedData
-        .map { PhotoDetailUiState.Success(it) }
+        .map {
+            when (it) {
+                is Result.Success -> PhotoDetailUiState.Success(it.data)
+                is Result.Error -> PhotoDetailUiState.Error
+            }
+        }
         .stateIn(
             scope = viewModelScope,
             started = SharingStarted.WhileSubscribed(stopTimeoutMillis = 5000),