fix(frontend) performance issues in main menu project selection (#2715)

* Prefactor: Move Project Selection List to dedicated component

* Use v-virtual-scroll for dynamic rendering
Removed custom dynamic rendering & scrolling logic
Use slide-y-transition to keep project list size stable during transition. This avoids issues with scrolling

* Make project tooltip lazy

* - Fixed code formatting
- Fixed error when navigating with keys in case there are no projects to select
- Removed eager=false prop from tooltip as this will be disabled globally in #2730

* Changed transition to avoid animation glitch
Fixed project tile height
Use horizontal bar to structure tiles
Extended project list height
Optimized project items computed

* Navigate on event to avoid navigating if project changed outside of menu

* PR Feedback

Author: grolu