Adding Phrases

This is an example of how to think differently.  "hello world"  is a
phrase.  I'm adding a class that holds phrases and a phrase  class.  The
phrase class defines a common id, text, and the language used.  This
lets phrases hold many phrase objects that can be the same phrase in
many languages.  This gives Phrases() the ability to translate a phrase
from one language to another.

Adding the HelloWorld.Shared.Fixtures project.  This is a NUnit testing
framework project.  NUnit is faster than MSTest so Nunit is preferred.
Nunit uses the term "Fixture" hence the project name and class name with
"Fixture".

There are three tests added in the PhrasesFixtures file.  Two of these
translate "hello  world" from  english to vietnamese and spanish.

Because Phrases() is generic it can hold any phrase text and language
you want.