[Partial fix for #1372]Added SimpleTypesExcludeFilter to exlcude validat...

...ion on simple types and also added tests to cover scenarios.

@yishaigalatzer @pranavkm @rynowak @harshgMSFT 

Note:
- This PR does not have comments. I will add them once we agree upon the changes.
The simple way to do it is to just create a private class and use Json.Net to deserialize it. It's a pretty common pattern in our tests. 

Often **the most** important thing about a test is the ability to look at the code and understand what it's testing, so if this gets you closer encoding what's really important about the test then it's worth doing.