Add Statistics category to the contextual navigation at a project level

At a project level:

• Add new Statistics category to the contextual navigation (sidebar).

• Move Charts (currently within Repository) to the new Statistics category.

• Move Cycle Analytics to the new Statistics category.

• Move Contributors to the new Statistics category.

• Move Members to the new Statistics category.

Research to support this decision: ux-research#43 (closed)

Order of the new elements

• The Statistics category will appear below CI/CD and above Wiki.

• The ordering within the statistics category is as follows: Cycle Analytics, Contributors, Members and Charts.

• Based on the points above, the new structure of the contextual sidebar at a project level will be as follows:

• Project
  • Details
  • Activity
• Repository
  • Files
  • Commits
  • Branches
  • Tags
  • Graph
  • Compare
  • Locked Files
  • Snippets
• Registry
• Issues
  • List
  • Boards
  • Labels
  • Service Desk
  • Milestones
• Merge Requests
• CI/CD
  • Pipelines
  • Jobs
  • Schedules
  • Environments
  • Charts
• Statistics
  • Cycle Analytics
  • Contributors
  • Members
  • Charts
• Wiki
• Settings (if applicable)

cc @victorwu