Add FlipperServerDisconnectedError to prevent excessive error logging

Reviewed By: passy

Differential Revision: D51393196

fbshipit-source-id: f49857b397a3fb629ad44f89a4c59b12ba2f67c4

desktop/flipper-common/src/utils/errors.tsx

@@ -96,6 +96,12 @@ export class NoLongerConnectedToClientError extends Error {
   name: 'NoLongerConnectedToClientError';
 }
 
+export class FlipperServerDisconnectedError extends Error {
+  constructor(public readonly reason: 'ws-close') {
+    super(`Flipper Server disconnected. Reason: ${reason}`);
+  }
+}
+
 declare global {
   interface Error {
     interaction?: unknown;