Convert bunch of utils to TS

src/utils/Receipt.js

@@ -1,36 +0,0 @@
-/*
-Copyright 2016 OpenMarket Ltd
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
-/**
- * Given MatrixEvent containing receipts, return the first
- * read receipt from the given user ID, or null if no such
- * receipt exists.
- *
- * @param {Object} receiptEvent A Matrix Event
- * @param {string} userId A user ID
- * @returns {Object} Read receipt
- */
-export function findReadReceiptFromUserId(receiptEvent, userId) {
-    const receiptKeys = Object.keys(receiptEvent.getContent());
-    for (let i = 0; i < receiptKeys.length; ++i) {
-        const rcpt = receiptEvent.getContent()[receiptKeys[i]];
-        if (rcpt['m.read'] && rcpt['m.read'][userId]) {
-            return rcpt;
-        }
-    }
-
-    return null;
-}