Loading select options takes too long

When trying to edit a Hylem Sequence the select options for each and every entity with selections are fully loaded which in case of large Hylem Sequences might take minutes. This has to be fixed to make the form usable.

Possible solution could be to store the different select options lists somewhere and add some click event handlers to the select lists to only load the options on click.

The click event stuff might also be working with directly querying the API.