Improve logging Angular implementation

[atarix83]

This issue relates to DSpace/DSpace#3303
To get the best from this logging mechanism, the Angular UI should be improved by adding to all the requests these two new custom header

• X-CORRELATION-ID with a random generated uuid or any hard to conflict string generated at the application load and keep stable for all the browsing session

• X-REFERRER to note the page that has generated the REST request