feat(sidebar): context menu to control connections COMPASS-9392

[kraenhansen]

Description

The original design showed just the "Import connections" and "Export connections" and I believe this is a mistake as it makes sense for the actions which are "above the menu fold" (collapsing connections and creating a new) would also show from the context menu.

right-click-sidebar-connections.mov

Merging this PR will:

• Reuse the existing action items to show a context menu containing four items:
  • Collapse all connections
  • Add new connection
  • Import connections
  • Export connections

Checklist

• New tests and/or benchmarks are included
• Documentation is changed or added
• If this change updates the UI, screenshots/videos are added and a design review is requested
• I have signed the MongoDB Contributor License Agreement (https://www.mongodb.com/legal/contributor-agreement)

Motivation and Context

• Bugfix
• New feature
• Dependency update
• Misc

Open Questions

Dependents

Types of changes

• Backport Needed
• Patch (non-breaking change which fixes an issue)
• Minor (non-breaking change which adds functionality)
• Major (fix or feature that would cause existing functionality to change)