Mark the recovery key as sensitive when copying it to the clipboard

The recovery key was copied without EXTRA_IS_SENSITIVE, so Android 13+
showed it in the clipboard preview and keyboards could store it in
their clipboard history.

Add an isSensitive option to CopyToClipboardUseCase and
Context.copyToClipboard, and set it when copying the recovery key.

features/securebackup/impl/src/main/kotlin/io/element/android/features/securebackup/impl/setup/SecureBackupSetupView.kt

@@ -122,6 +122,7 @@ private fun Content(
             context.copyToClipboard(
                 text = formattedRecoveryKey,
                 toastMessage = toastMessage,
+                isSensitive = true,
             )
             state.eventSink.invoke(SecureBackupSetupEvent.RecoveryKeyHasBeenSaved)
         }