Reset autofocus when executing a job, so that focus step is applied properly when checked.

Summary:
When executing a sequence, the first job having the focus step checked was executing a focus procedure.
Once the focus procedure was done, no further focus procedure would be requested by Scheduler.

With this change, Scheduler always requests a focus procedure when a job explicitly requires it.
If the focus procedure needs to be run periodically, its period must be set in the capture sequence, and the Focus step unchecked.

Test Plan:
The test can be run with the Simulator profile. Focus procedure will sometimes abort, but most of the time succeed.
Create a schedule plan with three targets with only Track and Focus checked, and short capture, and start Scheduler.
Scheduler runs the first job, slews to target and executes the focus procedure before capturing.
Scheduler shifts to the second job, slew to target, and:

• without this change, proceeds to capture even though the Focus step is checked.
• with this change, executes the focus procedure prior to capture.

Situation is the same for all subsequent jobs.

Reviewers: mutlaqja, wreissenberger

Reviewed By: mutlaqja, wreissenberger

Subscribers: kde-edu

Tags: KDE Edu

Differential Revision: https://phabricator.kde.org/D22380