Add an option for case sensitive (or not) comparisons for string IDs

[julienadam]

In the end it would be nice to be able to just compare IDs and not care about case sensitivity.

[vbfox]

Interesting, I wonder if it should be something specific to string or given as an extension point everywhere.

So the choices are :

• Specific code for strings CaseSensitive: false
• A Normalize method that could be implemented per-type (Changing the value stored in the ID)
• A Compare method that could be implemented per-type (Keeping the value stored in the ID but considering values equals)