Update Roadmap Left Pane to support Nested Folder & Report Navigation Similar to Notebooks tab

Being able to navigate through reports using a nested folder structure all in one place on the left pane would help provide consistency across Aha! Along with this, I would recommend adding a right-click context menu similar to what is available in the Notebooks left-pane as well. I find that this navigation method is easier to follow than the current breadcrumb approach used on the roadmaps tab.