[MM-40406] Add more singletons, refactor main.ts into pieces, add tests and some cleanup + tests for additional coverage (#1890)

* Refactor main.ts dependencies into singleton pattern

* Split main.ts into testable pieces, some other refactoring for singleton pattern

* Unit tests for main/app/app

* Unit tests for main/app/config

* Unit tests for main/app/initialize

* Unit tests for main/app/intercom

* Unit tests for main/app/utils

* Add some more tests to get to 70% coverage

* Fix for linux

* Fix for alternate data dir paths

* Fix E2E test

src/main/constants.ts

@@ -0,0 +1,36 @@
+// Copyright (c) 2016-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+/* istanbul ignore file */
+
+import path from 'path';
+
+import {app, ipcMain} from 'electron';
+
+import {UPDATE_PATHS} from 'common/communication';
+
+let userDataPath;
+
+export let configPath = '';
+export let allowedProtocolFile = '';
+export let appVersionJson = '';
+export let certificateStorePath = '';
+export let trustedOriginsStoreFile = '';
+export let boundsInfoPath = '';
+
+export function updatePaths(emit = false) {
+    userDataPath = app.getPath('userData');
+
+    configPath = `${userDataPath}/config.json`;
+    allowedProtocolFile = path.resolve(userDataPath, 'allowedProtocols.json');
+    appVersionJson = path.join(userDataPath, 'app-state.json');
+    certificateStorePath = path.resolve(userDataPath, 'certificate.json');
+    trustedOriginsStoreFile = path.resolve(userDataPath, 'trustedOrigins.json');
+    boundsInfoPath = path.join(userDataPath, 'bounds-info.json');
+
+    if (emit) {
+        ipcMain.emit(UPDATE_PATHS);
+    }
+}
+
+updatePaths();