Improve fork page design

What does this MR do?

This MR introduces improved fork page design implementing lazy loading groups except own namespace. This greatly improves handling of use cases when we have tons of possible fork targets Main issue: #212456 (closed)

Screenshots

Responsive

	before	after
desktop
tablet
mobile

Custom states

	before	after
Unable to fork because of project limit for user
Fork already exists
Empty state
Empty state after filtering	N/A

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• [-] Informed Infrastructure department of a default or new setting change, if applicable per definition of done