Key backup Rust API adoption (#1952)

* Adopt Rust side secure backup APIs (incomplete, based on poljar/backup-pr)

* Implement the home screen recovery key confirmation banner.

* Update with the latest Rust changes.

The loading button for .unknown was incorrect. It should be treated as disabled.

---------

Co-authored-by: Doug <douglase@element.io>

ElementX/Sources/Services/SecureBackup/SecureBackupControllerProtocol.swift

@@ -28,6 +28,8 @@ enum SecureBackupRecoveryKeyState {
 }
 
 enum SecureBackupKeyBackupState {
+    /// Any state where backups couldn't have been enabled but we didn't explicitly disable them on this client.
+    /// For all intents and purposes, within the client, this can be treated as `disabled`.
     case unknown
     case enabling
     case enabled
@@ -36,11 +38,13 @@ enum SecureBackupKeyBackupState {
 }
 
 enum SecureBackupControllerError: Error {
-    case failedEnablingKeyBackup
-    case failedDisablingKeyBackup
+    case failedEnablingBackup
+    case failedDisablingBackup
     
     case failedGeneratingRecoveryKey
     case failedConfirmingRecoveryKey
+    
+    case failedFetchingSessionState
 }
 
 // sourcery: AutoMockable
@@ -49,14 +53,14 @@ protocol SecureBackupControllerProtocol {
     
     var keyBackupState: CurrentValuePublisher<SecureBackupKeyBackupState, Never> { get }
     
-    var isLastSession: Bool { get }
-    
-    func enableBackup() async -> Result<Void, SecureBackupControllerError>
-    func disableBackup() async -> Result<Void, SecureBackupControllerError>
+    func enable() async -> Result<Void, SecureBackupControllerError>
+    func disable() async -> Result<Void, SecureBackupControllerError>
     
     func generateRecoveryKey() async -> Result<String, SecureBackupControllerError>
     func confirmRecoveryKey(_ key: String) async -> Result<Void, SecureBackupControllerError>
     
+    func isLastSession() async -> Result<Bool, SecureBackupControllerError>
+    
     func waitForKeyBackup() async
 }