[Firefox][Awesomebar] Two new search engines

I will propose to add two new search options to awesomebar:

  1. Current site search engine
  2. Search text on this site

Firstly, there is not necessary of adding first search engine. Mozilla should create standard to read information from meta (or introduce JS API) to add search engine to browser, so pages could integrate with awesomebar. That will decrease privacy, but i am open to discussion about how to prevent this. This is necessary to reduce some web pages cluttering. For example - I go to Youtube.com and type Firefox and enter to force page display any movies related to Firefox. This (“virtual”) search engine would be default.

New tab will use default search engine set by user.

Second option is to search for text on web page. Some users may do not known how to search on web page (click CTRL+F) and search in awesomebar could be more intuitive.