Add "detail-mode" to page_search template

Before this the quote of an annotation was missing from the search page.
Now it has been working similarly as the viewer page.
Whitespace correction for page_search.html
Page search now can search for quotes too.

- Only searches for quote in the top-level annotations
- Also if another search term is given it will only match for top-level annotations
- Quote hits are displayed in detail mode
Highlight quote hits for page_search

The quote search terms are now highlighted in the annotations quote.
Hovering above an annotation card highlights its quote for search results too.

Not it has the same behaviour as the Viewer in this fascion.
Merge pull request #627 from hypothesis/617-search-oddities

Fixed some page search issues. (See #617 for details.)