Migrate to convertToSlipData from stripes-util - Requests

Purpose:

In settings -> circulation -> staff slips we create template that contain token. When we try print this template in our modules checkin, requests, requests-mediated and etc we need match real data and token from template. For this match responsibel convertToSlipData function and supporting functions. And in each of modules checkin, requests, requests-mediated and etc we have own exemplar of convertToSlipData function and supporting functions. This mean that when we add new token in settings -> circulation -> staff slips we need update convertToSlipData function in all modules checkin, requests, requests-mediated and etc. For resolve this problem we move convertToSlipData function and supporting functions (to one please) to stripes-util for reuse for modules checkin, requests, requests-mediated and etc.

Solution:

Reuse from stripes-util.