feat: vertical tabs

[lcottercertinia]

Is your feature request related to a problem?

Monitors tend to have more horizontal than vertical space using vertical tabs would free up some space.

Describe the solution you'd like

1. vertical tabs instead of horizontal for Timeline etc
2. Use the side bar in vscode to show the tabs, then it can be placed right of left.
3. Add an option to enable / disable based on preference.

Describe alternatives you've considered

vertical tabs in the webview but that would take up loads of room when vscode sidebar is open

Additional context

Add any other context or screenshots about the feature request here