Replace technical & unlocalized error message with "Connection lost"

src/room/GroupCallView.tsx

@@ -58,10 +58,9 @@ import { callEventAudioSounds } from "./CallEventAudioRenderer";
 import { useLatest } from "../useLatest";
 import { usePageTitle } from "../usePageTitle";
 import {
+  ConnectionLostError,
   E2EENotSupportedError,
   ElementCallError,
-  ErrorCode,
-  RTCSessionError,
   UnknownCallError,
 } from "../utils/errors.ts";
 import { GroupCallErrorBoundary } from "./GroupCallErrorBoundary.tsx";
@@ -142,14 +141,7 @@ export const GroupCallView: FC<Props> = ({
   useTypedEventEmitter(
     rtcSession,
     MatrixRTCSessionEvent.MembershipManagerError,
-    (error) => {
+    (error) => setExternalError(new ConnectionLostError()),
-      setExternalError(
-        new RTCSessionError(
-          ErrorCode.MEMBERSHIP_MANAGER_UNRECOVERABLE,
-          error.message ?? error,
-        ),
-      );
-    },
   );
   useEffect(() => {
     // Sanity check the room object

src/utils/errors.ts

@@ -13,7 +13,6 @@ export enum ErrorCode {
    */
   MISSING_MATRIX_RTC_FOCUS = "MISSING_MATRIX_RTC_FOCUS",
   CONNECTION_LOST_ERROR = "CONNECTION_LOST_ERROR",
-  MEMBERSHIP_MANAGER_UNRECOVERABLE = "MEMBERSHIP_MANAGER_UNRECOVERABLE",
   /** LiveKit indicates that the server has hit its track limits */
   INSUFFICIENT_CAPACITY_ERROR = "INSUFFICIENT_CAPACITY_ERROR",
   E2EE_NOT_SUPPORTED = "E2EE_NOT_SUPPORTED",
@@ -25,7 +24,6 @@ export enum ErrorCategory {
   /** Calling is not supported, server misconfigured (JWT service missing, no MSC support ...)*/
   CONFIGURATION_ISSUE = "CONFIGURATION_ISSUE",
   NETWORK_CONNECTIVITY = "NETWORK_CONNECTIVITY",
-  RTC_SESSION_FAILURE = "RTC_SESSION_FAILURE",
   CLIENT_CONFIGURATION = "CLIENT_CONFIGURATION",
   UNKNOWN = "UNKNOWN",
   // SYSTEM_FAILURE / FEDERATION_FAILURE ..
@@ -84,11 +82,6 @@ export class ConnectionLostError extends ElementCallError {
   }
 }
 
-export class RTCSessionError extends ElementCallError {
-  public constructor(code: ErrorCode, message: string) {
-    super("RTCSession Error", code, ErrorCategory.RTC_SESSION_FAILURE, message);
-  }
-}
 export class E2EENotSupportedError extends ElementCallError {
   public constructor() {
     super(