Verifies Sources don’t contain duplicate bundle IDs

AltStore assumes all apps have unique bundle IDs per source. Weird bugs can occur when this is not the case (such as merging multiple store listings into one), so we now verify upfront whether source contains duplicate bundle IDs before saving.

AltStore/Sources/SourcesViewController.swift

@@ -239,7 +239,14 @@ private extension SourcesViewController
                 {
                 case .success: break
                 case .failure(OperationError.cancelled): break
-                case .failure(let error): self.present(error)
+                    
+                case .failure(var error as SourceError):
+                    let title = String(format: NSLocalizedString("“%@” could not be added to AltStore.", comment: ""), error.$source.name)
+                    error.errorTitle = title
+                    self.present(error)
+                    
+                case .failure(let error as NSError):
+                    self.present(error.withLocalizedTitle(NSLocalizedString("Unable to Add Source", comment: "")))
                 }
                 
                 self.collectionView.reloadSections([Section.trusted.rawValue])
@@ -263,10 +270,6 @@ private extension SourcesViewController
                 let sourceName = source.name
                 let managedObjectContext = source.managedObjectContext
                 
-                #if !BETA
-                guard let trustedSourceIDs = UserDefaults.shared.trustedSourceIDs, trustedSourceIDs.contains(source.identifier) else { throw SourceError(code: .unsupported, source: source) }
-                #endif
-                
                 // Hide warning when adding a featured trusted source.
                 let message = isTrusted ? nil : NSLocalizedString("Make sure to only add sources that you trust.", comment: "")
                 
@@ -311,9 +314,10 @@ private extension SourcesViewController
         }
         
         let nsError = error as NSError
-        let message = nsError.userInfo[NSDebugDescriptionErrorKey] as? String ?? nsError.localizedRecoverySuggestion
+        let title = nsError.localizedTitle // OK if nil.
+        let message = [nsError.localizedDescription, nsError.localizedDebugDescription, nsError.localizedRecoverySuggestion].compactMap { $0 }.joined(separator: "\n\n")
         
-        let alertController = UIAlertController(title: error.localizedDescription, message: message, preferredStyle: .alert)
+        let alertController = UIAlertController(title: title, message: message, preferredStyle: .alert)
         alertController.addAction(.ok)
         self.present(alertController, animated: true, completion: nil)
     }