Add case-insensitive option for user by email search

@konrad.sopala @dan.woda Any update on this?

We can’t use this endpoint due to most of our users using enterprise connectors so their email addresses can be in any casing. We’re using the GET /api/v2/users endpoint as a workaround. This causes different issues though since it’s not immediately consistent. We’ve had issues where new users haven’t showed up in that endpoint for several minutes as well as out of date data being returned.