Altered specs that click capitalised New Snippet button
Applied review feedback missed in Changes `.no-comment` `opactiy: 0.5` to `opacity: .5`
Added `.btn-wide-on-xs` and applied to snippet buttons
No longer shows New Snippet button to users who aren't able to create a new snippet in the given context.
Also removes the plus icon from the New Snippet buttons, as they're no longer used in other creation buttons.
Fixes#14595.
- Split up SnippetsController into separate dashboard and explore sections.
- Use consistent page titles, header titles and sidebars between dashboard and explore sections when signed in or not.
Luke Bennett