Enable @typescript-eslint/explicit-member-accessibility on /src (#9785)

* Enable `@typescript-eslint/explicit-member-accessibility` on /src

* Prettier

src/utils/DMRoomMap.ts

@@ -40,7 +40,7 @@ export default class DMRoomMap {
     private hasSentOutPatchDirectAccountDataPatch: boolean;
     private mDirectEvent: { [key: string]: string[] };
 
-    constructor(private readonly matrixClient: MatrixClient) {
+    public constructor(private readonly matrixClient: MatrixClient) {
         // see onAccountData
         this.hasSentOutPatchDirectAccountDataPatch = false;