Improve the header section on Workspace details page

MR: Pending

Description

As part of our new designs for Workspaces, we need to improve the existing header section (Implement header for workspace details page wit... (#566544)) so that users can quickly identify the workspace, its current status, and associated repository information.

Visual Changes

Acceptance criteria

• Display workspace description or name prominently in the header
• Add coloured status indicator dot next to workspace name
• Show repository path (e.g., "GitLab.org/gitlab-ui") with clickable link to repository
• Display branch information with change counts and commits behind
• Branch information is clickable and links to the branch view

TODO: Implementation plan

• Implement workspace title display using workspace name or description
• Add status indicator component using existing enhanced status indicator patterns
• Display repository information with proper link generation to GitLab repository
• Implement branch information display using data from branch & local files information
• Add proper click handlers for repository and branch navigation
• Style header section following GitLab design system header patterns

Technical Notes

• Status Indicator: Reuse enhanced status indicator component with coloured dots from previous workspace card work (See: Implement enhanced workspace status indicators ... (#562357) • Unassigned • Backlog)
• Branch Data: Uses branch and local changes information implemented in Display workspace branch details in workspace l... (#563085) • Unassigned • Backlog & Add workspace file changes field definition and... (#565017) • Unassigned • Backlog