[Release_8] Opencast Studio link enhancements: hidden Series + ACLs

[ferishili]

This PR fixes #382

Description

It has been requested to make it possible to pass the User ACLs also to Studio, as well as hiding the series id field in the studio!
Please refer to #382 (comment) for more info!

Solution

• Make the query param prepration a bit more cleaner by using arrays etc.
• Add seriesField=hidden into the query params of Studio Link
• Add a new function: ACLtoXML->getStudioACLObjectNotation which is responsible to convert the acl entries into an acl notation object string consumable by Studio via elan-ev/opencast-studio #1212
• Pass that ACL notation object string as "upload.acl" param to the query params string

To TEST

You would need to:

• Patch this PR
• Patch elan-ev/opencast-studio #1212
• Adjust your Roles in Plugin Config > Settings > Groups & Roles
• Make sure Studio is configured!
• Go to a series repo object in a course with a user that has Studio Upload Right
• Click on the Opencast Studio button
• Make sure to upload any video in studio and validate the changes:
  • The series ID has to be "hidden" in the Studio UI upload form.
  • After the video is upload the ACLs must be presented to the Access policy list of that event as it would come from a normal video upload from ILIAS Plugin!