Remove WindowManager, separate functionality into smaller modules (#2682)

* Move sendToRenderer to respective singletons

* Move to using ViewManager call for getting view by webContentsId

* Move show and create logic to main window, handle deep linking seperately

* Move resizing logic and event handing to mainWindow

* Move server switching logic to main/app

* Move tab switching logic to main/app, rely on showById for most usage

* Migrate remaining functions, remove windowManager objects, set up imports for self-contained singletons

* Fix E2E tests

* Update src/main/app/servers.ts

Co-authored-by: Elias Nahum <nahumhbl@gmail.com>

---------

Co-authored-by: Elias Nahum <nahumhbl@gmail.com>

e2e/specs/server_management/configure_server_modal.test.js

@@ -86,6 +86,7 @@ describe('Configure Server Modal', function desc() {
             url: 'http://example.org/',
             name: 'TestTeam',
             order: 0,
+            lastActiveTab: 0,
             tabs: [
                 {
                     name: 'TAB_MESSAGING',