Multi file uploads (#4358)

* Allow MediaPickerScreen users to select the media selection mode (single or multiple)

* Fix cancellation

* Add support for multiple media URLs on the MediaUploadPreviewScreen.

* Support processing more URLs on the `MediaUploadingPreprocessor` and sending more on the `MediaUploadPreviewScreen`

* Add feature flag for `multipleAttachmentUploadEnabled`

* Add a label showing the current preview item index in the MediaUploadPreviewScreen

* Add support for dragging and dropping or pasting multiple items at the same time.

* Support sharing more than one file through the share extension.

* Limit the number of items that can be shared in one go to 5.

* Fix unit tests

* Fix incorrect fatal error when dealing with single selection media pickers.

* Document the `multipleAttachmentUploadEnabled` usage in the context of the MediaPicker.

* Use a task group for processing selected media in the photo library picker.

* Use a task group for processing multiple selected media in the MediaUploadingPreprocessor

* Switch the maximum number of items that can be shared to 10.

* Allow multiple items to be pasted at the same time.

ElementX/Sources/Application/Settings/AppSettings.swift

@@ -16,11 +16,13 @@ import SwiftUI
 protocol CommonSettingsProtocol {
     var logLevel: LogLevel { get }
     var traceLogPacks: Set<TraceLogPack> { get }
+    var bugReportRageshakeURL: RemotePreference<RageshakeConfiguration> { get }
+    
     var enableOnlySignedDeviceIsolationMode: Bool { get }
     var enableKeyShareOnInvite: Bool { get }
-    var hideQuietNotificationAlerts: Bool { get }
     var threadsEnabled: Bool { get }
-    var bugReportRageshakeURL: RemotePreference<RageshakeConfiguration> { get }
+    var hideQuietNotificationAlerts: Bool { get }
+    var multipleAttachmentUploadEnabled: Bool { get }
 }
 
 /// Store Element specific app settings.
@@ -59,6 +61,7 @@ final class AppSettings {
         case threadsEnabled
         case developerOptionsEnabled
         case sharePosEnabledV2
+        case multipleAttachmentUploadEnabled
         
         // Doug's tweaks 🔧
         case hideUnreadMessagesBadge
@@ -70,6 +73,16 @@ final class AppSettings {
     /// UserDefaults to be used on reads and writes.
     private static var store: UserDefaults! = UserDefaults(suiteName: suiteName)
     
+    /// Whether or not the app is a development build that isn't in production.
+    static var isDevelopmentBuild: Bool = {
+        #if DEBUG
+        true
+        #else
+        let apps = ["io.element.elementx.nightly", "io.element.elementx.pr"]
+        return apps.contains(InfoPlistReader.main.baseBundleIdentifier)
+        #endif
+    }()
+    
     #if IS_MAIN_APP
         
     static func resetAllSettings() {
@@ -135,16 +148,6 @@ final class AppSettings {
     
     // MARK: - Application
     
-    /// Whether or not the app is a development build that isn't in production.
-    static var isDevelopmentBuild: Bool = {
-        #if DEBUG
-        true
-        #else
-        let apps = ["io.element.elementx.nightly", "io.element.elementx.pr"]
-        return apps.contains(InfoPlistReader.main.baseBundleIdentifier)
-        #endif
-    }()
-    
     /// The last known version of the app that was launched on this device, which is
     /// used to detect when migrations should be run. When `nil` the app may have been
     /// deleted between runs so should clear data in the shared container and keychain.
@@ -362,6 +365,8 @@ final class AppSettings {
     @UserPreference(key: UserDefaultsKeys.traceLogPacks, defaultValue: [], storageType: .userDefaults(store))
     var traceLogPacks: Set<TraceLogPack>
     
+    let bugReportRageshakeURL: RemotePreference<RageshakeConfiguration> = .init(Secrets.rageshakeURL.map { .url(URL(string: $0)!) } ?? .disabled) // swiftlint:disable:this force_unwrapping
+    
     /// Configuration to enable only signed device isolation mode for  crypto. In this mode only devices signed by their owner will be considered in e2ee rooms.
     @UserPreference(key: UserDefaultsKeys.enableOnlySignedDeviceIsolationMode, defaultValue: false, storageType: .userDefaults(store))
     var enableOnlySignedDeviceIsolationMode
@@ -370,13 +375,14 @@ final class AppSettings {
     @UserPreference(key: UserDefaultsKeys.enableKeyShareOnInvite, defaultValue: false, storageType: .userDefaults(store))
     var enableKeyShareOnInvite
 
-    @UserPreference(key: UserDefaultsKeys.hideQuietNotificationAlerts, defaultValue: false, storageType: .userDefaults(store))
-    var hideQuietNotificationAlerts
-    
     @UserPreference(key: UserDefaultsKeys.threadsEnabled, defaultValue: false, storageType: .userDefaults(store))
     var threadsEnabled
     
-    let bugReportRageshakeURL: RemotePreference<RageshakeConfiguration> = .init(Secrets.rageshakeURL.map { .url(URL(string: $0)!) } ?? .disabled) // swiftlint:disable:this force_unwrapping
+    @UserPreference(key: UserDefaultsKeys.hideQuietNotificationAlerts, defaultValue: false, storageType: .userDefaults(store))
+    var hideQuietNotificationAlerts
+    
+    @UserPreference(key: UserDefaultsKeys.multipleAttachmentUploadEnabled, defaultValue: isDevelopmentBuild, storageType: .userDefaults(store))
+    var multipleAttachmentUploadEnabled
 }
 
 extension AppSettings: CommonSettingsProtocol { }