Allow disabling line highlighting on click in PhabricatorSourceCodeView

Summary:
There may be times when we don't want lines in some embeded source
code to be highlighted on click, this adds that functionality.

Also use the functionalty in PasteEmbedView

Test Plan:

• View paste, make sure everything works.
• Embed paste in comment, make sure everything works apart from click hl

Reviewers: epriestley

Reviewed By: epriestley

CC: Korvin, aran

Maniphest Tasks: T3881

Differential Revision: https://secure.phabricator.com/D7111