Added IT Exception process and color to administrative access criteria

This MR includes:

1. Added Information Security Policy Exception Management process

• This was provided by @cciresi and reviewed with @MFarber.

@kathyw Please review and approve.

1. Administrative access definition

/cc @cciresi @pmachle @jhurewitz @gitlab-com/gl-security/compliance @pharrison

This is to support request outlined by @pmachle