Remove Monitoring Level option from StartOrder-call

[johannesheucher-gip]

At the moment, there is the option to pass a Monitoring Level along with the startOrder call. This has the effect, that the executed order respects that Monitoring Level. In contrast to that, all induced orders won't use that Monitoring Level but that defined in their respective Order Type. This makes the feature of passing a Monitoring Level along with the startOrder endpoint kind of powerless and misleading.
Additionally, it should not be the responsibility of the GUI to define a Monitoring Level for an executed order (and much less at the time of calling the order).
This should only be defined by the respective Order Type.

Exceptions

There are use cases, where the Monitoring Level should be passed during execution, e. g. for the Workflow Launcher or for Order Input Sources.

Proposed Solution

Remove the Monitoring Level option from the startOrder call and find a way to cope with the exceptions.