[Spike] Navigate repo with a file tree

Context

This issue aims at covering a spike to validate the implementation plan for #19530 (closed).

It should cover:

• Double-check existence of reusable components from the MR/Rapid Diffs effort
• Check if all APIs exist to achieve the desired functionality

Expected outcome:

• a list of steps to fully implement this file tree in the repository including folders and blob views

Task list

• familiarise with Navigate repo with a file tree issue
• Investigate MR tree component for reusability
• Document necessary HTML structure for a correct tree view pattern
• Document existing API
• Map out data flow
• Performance measuring
• Architecture planning
• Identify blockers and dependencies
• Review
• Prepare detailed implementation plan
• Create epic and issues