* Add DS nav page switcher behind overleaf-library flag
- Add shared DsNavPageSwitcher component (Library/Projects nav links + logo)
- Show page switcher in projects sidebar when overleaf-library flag enabled
- Hide 'All projects' filter and sidebar New Project button behind flag
- Move New Project button to content area header when flag enabled
- Prevent full page reload when clicking active nav item
- Change Upgrade button to premium variant when flag enabled
- Add overleaf-library split test to ProjectListController
- Add library-page class to remove rounded corner on /library
- Add Cypress component tests for DsNavPageSwitcher
Closes#33092
GitOrigin-RevId: 2e348da8307bf944d481b54b3a2bcc2eb319e18e
* Convert event-tracking to TypeScript
* Convert local-storage to TypeScript
* Convert mapSeries to TypeScript
* Convert SessionStorage to TypeScript
* Convert account-upgrade to TypeScript
* Convert isValidTeXFile to TypeScript
* Convert date functions to TypeScript
* Convert EventEmitter to TypeScript
* Convert isNetworkError to TypeScript
* Convert webpack-public-path to TypeScript
* Convert displayNameForUser to TypeScript
GitOrigin-RevId: 79c5a2d1101fcd520f3116f0f4af29d974189d94