BREAKING CHANGE: Removes HttpExtensions

Removes the HttpExtensions and related tests.

BREAKING CHANGE: This removes the ValidateUri extension method.

Author: BenjaminMichaelis

IntelliTect.Multitool.Tests/Extensions/HttpExtensionsTests.cs

@@ -57,8 +57,6 @@
 - StringExtensions: Extension methods for `System.String`
   - `ValidateUrlString`: Extension method to validate a URL string by checking to make sure the string is formatted correctly.
   - `CreateUrlSlug`: Extension method modify a string so that it is URL compatible
-- HttpExtensions: Extension methods for `System.Net.Http.HttpClient`
-  `ValidateUri`: Extension methods to validate a Uri by attempting to make a GET request to it.
 - SystemLinqExtensions
   - `WhereNotNull`: Extension method to allow return of non-null value from a null object.
     - Sample: