Role Filters Improvements

Hi zach

I have multiple users and services in Pritunl Zero and I am doing the assignment over roles. I can now filter users or services by various criteria, such as username, service ID, service name and role. However, the role filter seems a little odd: I always have to enter the full name of the role; entering just part of it does not work. It also seems as though the role filter is case sensitive.

I have added to the code a button to toggle between partial matching. This will be included in the next release.