Remove siteDetails.less

[luixxiul]

Describe the issue you encountered: Remove siteDetails.less

This file is widely used on about pages, and some of them require another LESS file which imports siteDetails.less (X.less requires history.less, which imports siteDetails.less, for example). Creating the framework with Aphrodite reduces such cases and makes it easy to remove siteDetails.less completely.

So far these elements have been created into custom components:

• <SectionTitle> (Create sectionTitle.js #8237)
• <SiteDetailsPageHeader>
  • <SiteDetailsPageHeader actions> inside the Header (ref history.js and bookmarks.js)
• <SiteDetailsPageContent>
• TBA

Any related issues: #8165