ListView separator has a small left margin

**ListMenu** ListView in MainPage.xaml has a small left margin (but not one on the right hand side) creating asymmetry in the page. This is related to [this](https://stackoverflow.com/questions/31537196/ios-9-uitableview-separators-insets-significant-left-margin) and [this](https://stackoverflow.com/questions/26519248/how-to-set-the-full-width-of-separator-in-uitableview).