Add bidi isolation to language annotations

Create a bidi-isolation class to use in all bidi-isolation cases
and attach it to the language annotation. The specific bidi-isolation
class will help in the (many) cases where the method to isolate the
text in CSS changes.

Change-Id: Id0fa463b3e9baae9a55eceee583fa7c51cfb09f6
Merge "Add bidi isolation to language annotations"