form values not available in initialiser

Causes a problem with behaviours that set a default value.

If you fill in a desc, then change the project to one that sets a default value via an initialiser, the initialiser cannot check if the field is currently empty, so it overwrites anything a user has already entered.

Also, you cannot currently get the parentIssueId (when creating a subtask) in an initialiser.

Most other issue fields (like assignee) can't be retrieved through their formFields in an initialiser as well, though they can be retrieved from the underlyingIssue object.