Add logic for modules caching

Such files as cache-restore.ts, cache-utils.ts, constants.ts,
cache-save.ts we added. Main.ts file now incorporates logic for using
files mentioned above.

src/cache-restore.ts

@@ -0,0 +1,66 @@
+import * as cache from '@actions/cache';
+import * as core from '@actions/core';
+import * as glob from '@actions/glob';
+import path from 'path';
+import fs from 'fs';
+
+import {State, Outputs} from './constants';
+import {
+  getCacheDirectoryPath,
+  getPackageManagerInfo,
+  PackageManagerInfo
+} from './cache-utils';
+
+export const restoreCache = async (
+  packageManager: string, 
+  cacheDependencyPath?: string 
+) => {
+  const packageManagerInfo = await getPackageManagerInfo();
+  const platform = process.env.RUNNER_OS;
+
+  const cachePath = await getCacheDirectoryPath(
+    packageManagerInfo
+  );
+  
+  const goSumFilePath = cacheDependencyPath
+    ? cacheDependencyPath
+    : findGoSumFile(packageManagerInfo);
+  const fileHash = await glob.hashFiles(goSumFilePath);
+
+  if (!fileHash) {
+    throw new Error(
+      'Some specified paths were not resolved, unable to cache dependencies.'
+    );
+  }
+
+  const primaryKey = `go-cache-${platform}-${fileHash}`;
+  core.debug(`primary key is ${primaryKey}`);
+
+  core.saveState(State.CachePrimaryKey, primaryKey);
+
+  const cacheKey = await cache.restoreCache([cachePath], primaryKey);
+  core.setOutput('cache-hit', Boolean(cacheKey));
+
+  if (!cacheKey) {
+    core.info(`${packageManager} cache is not found`);
+    return;
+  }
+
+  core.saveState(State.CacheMatchedKey, cacheKey);
+  core.info(`Cache restored from key: ${cacheKey}`);
+};
+
+const findGoSumFile = (packageManager: PackageManagerInfo) => {
+  let goSumFile = packageManager.goSumFilePattern;
+  const workspace = process.env.GITHUB_WORKSPACE!;
+  const rootContent = fs.readdirSync(workspace);
+
+  const goSumFileExists = rootContent.includes(goSumFile);
+  if (!goSumFileExists) {
+    throw new Error(
+      `Dependencies file  go.sum is not found in ${workspace}. Supported file pattern: ${goSumFile}`
+    );
+  }
+
+  return path.join(workspace, goSumFile);
+};