Double uppercase issue

[shipsaw]

Description

This addresses an issue brought up in #1471 where attributes that ended in "ID" (or any sequence of upper-case letters) was not able to match with properties where those two letters were also both capitalized (i.e. "id", "Id"). I didn't see in the docs that case-insensitive matching was a requirement, but for many people it seems that it is implied.

Addressing this issue in the GetNameVariants method in StringExtensions.cs would seem to involve a lot of extra methods just to achieve a case-insensitive comparison, so I updated the Map method to create a new case-insensitive dictionary rather than simply referencing the previous one.

Purpose

This pull request is a:

• [x ] Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist

• [ x] I have added tests that prove my fix is effective or that my feature works
• [x ] I have added necessary documentation (if appropriate)