feat: added ContractScanner service class to handle fetching contracts from mirror node

tools/erc-repository-indexer/erc-contract-indexer/example.env

@@ -0,0 +1,3 @@
+HEDERA_NETWORK=
+MIRROR_NODE_URL=
+STARTING_POINT=

tools/erc-repository-indexer/erc-contract-indexer/jest.config.js

@@ -0,0 +1,29 @@
+/*-
+ *
+ * Hedera Smart Contracts
+ *
+ * Copyright (C) 2024 Hedera Hashgraph, LLC
+ *
+ * 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.
+ *
+ */
+
+module.exports = {
+  preset: 'ts-jest',
+  testEnvironment: 'node',
+  testPathIgnorePatterns: ['/node_modules/', '/dist/'], // Ignore these folders
+  moduleFileExtensions: ['ts', 'js', 'json', 'node'], // File extensions to be considered
+  transform: {
+    '^.+\\.ts$': 'ts-jest', // Transform TypeScript files
+  },
+};