Werk #15967: event console: add site property to the event console endpoints

Event console IDs are integers beginning from 1, both for the main site & for remote sites. This means that the same event console ID can exist on more than one site at the same time. This caused problems when calling the DELETE endpoint as we weren't sure which ID the client wanted to delete. To get around this problem, we have introduced a "site_id" field. The site_id together with the event console ID combination is unique and therefore solves this issue.

show_event: site_id is now mandatory show_events: site_id is now optional update_and_acknowlege: site_id is now mandatory update_and_acknowledge_multiple: site_id is now optional change_state: site_id is now mandatory change_state_multiple: site_id is now optional archive_events: site_id is now mandatory

To the list of all Werks