[BUG] Toolbar back button bad

[Drewbi]

[APP]
Problem
Currently our back button links straight back to the dashboard no matter where it's pressed.

Where/When
On any page with a back button, eg /sessions/:sessionid

Desired behavior
Should go logically out one level. eg clicking back on /sessions/:sessionid should go back to /sessions and clicking it again should go back to /. This is different to just doing history.go(-1) as this would cycle back through every page you've visited before getting back to the dashboard.

Additional context
The back button lives inside Toolbar.vue