Update S110: Update the rule behavior to not count classes defined into another root namespace

[Evangelink]

The idea here is to rewrite the rule to automatically exclude types that are not defined in the same root namespace. We will keep the filteredClasses parameter to let users define some specific classes/namespace to ignore.

Examples:

• SonarSource.Product1.MyClass inherits from SonarSource.Product1.BaseClass then we count (both are defined in SonarSource root namespace.
• SonarSource.Product1.MyClass inherits from SonarSource.Common.BaseClass then we count (both are defined in SonarSource root namespace (even if product is different).
• SonarSource.Product1.MyClass inherits from System.Exception then we DON'T count (not defined in same root namespace).

RSPEC-110 needs to be updated for C#.