Improve left drawer appearance and behaviour

[bobheadxi]

The left drawer has some strange things going on right now:

• Expanding the last item "Ports" doesn't give any indication that "Ports" has subcategories, since subcategories are hidden by the "Settings" bar and there is no animation to indicate subcategory expansion
• Drawer automatically closes when selecting the "bottom-most" category (ie a category with no subcategories), a little jarring and unexpected. A better way to do this would be a little arrow button to display subcategories like done in Sync for reddit, and allow pressing a category to consistently close the drawer
• Layout looks a bit funky with the divider lines, again a drawer implementation like Sync would be nice
• "Settings" at the bottom has no visual cues or dividers other than the icon to separate it from menu items
• Odd drawer header spacing when no update is available (gap)

[michaelsam94]

I will work on first point