Sidebars in page layouts don't use Bootstrap grid system

https://us-cbp.github.io/cbp-style-guide/docs/foundation/layouts/type-content-navigation_wFixedSide.html

CSS is fixed width instead of using Bootstrap grid system (3 col side bar, 9 col content). If we can agree on the style direction, a corresponding issue to fix sidebar CSS will be needed in the CBP theme.

`
.sidebar {
    width: 350px; 
   min-width: 350px;
}
`