Reduced the amount of logs in the Scheduler.

Summary:
This change reduces the number of logs appearing in the Scheduler tab, restricting them to the log file.
This probably makes the UI more readable, but hides the internal processing somehow.
This also reduces a bit the requirement on translation, unless we also translate what is written to the log file.

Test Plan:
Use test vectors in 'Tests/scheduler' and observe the Scheduler log window.
Compare with the general KStars log. All information previously displayed is still there.

Reviewers: mutlaqja

Reviewed By: mutlaqja

Subscribers: kde-edu

Tags: KDE Edu

Differential Revision: https://phabricator.kde.org/D13229