Integrate workspaces popover in the repository view

MR: !125331 (merged)

Description

The goal of this issue is integrating the workspaces popover delivered as described in View and manage workspaces from the project’s r... (#395517 - closed) and Start, stop, restart, and delete a workspace fr... (#407355 - closed) in the Edit dropdown button that exists in the repository and file tree views.

Acceptance Criteria

• The user can see their non terminated workspaces for the opened project in the repository and file tree view.
• The user can change a Workspace’s state from the popover.
• The user can navigate to the New Workspace page.

Technical Requirements

• The workspaces popover is not visible when the remote_development_feature_flag is off.
• The workspaces popover is not visible in GitLab Community Edition.
• The workspaces popover doesn't query the GraphQL API when it isn't visible.