Provide case (in)sensitive filtering through collations

The task is discussed here:
https://github.com/Azure/project-hawaii/issues/11#issuecomment-1055396030

To achieve this we need to:
* know what collation a column is (and account for keeping this information up to date if the user can change it)
* know the equivalent collation of the existing collation which will provide case sensitive or insensitive comparison.
* make sure that the abovementioned equivalent collation exists / is recognized by the db (or if it doesn't exist, we error out)