MM-50347 Make desktop app landing page optional (#28421)

* fix: Make desktop app landing page optional

* Update i18n strings

* Fix linting and unit test

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Co-authored-by: Kiran <kiran@krinati.co>

webapp/platform/types/src/config.ts

@@ -64,6 +64,7 @@ export type ClientConfig = {
     EnableCustomTermsOfService: string;
     EnableDeveloper: string;
     EnableDiagnostics: string;
+    EnableDesktopLandingPage: 'true' | 'false';
     EnableEmailBatching: string;
     EnableEmailInvitations: string;
     EnableEmojiPicker: string;