Large task and order logs should be offered for download instead of being displayed in the browser log view window

Current Situation

• Task and order logs are displayed in the browser log view window.
• It is pointless to load very large logs in the log view window so that in case of the JobScheduler main log a download is already offered.

Desired Behavior

• Users should be able to decide if they want to display logs in a log view window or in their external editor after download.
• The log view window shows a link "download" for the respective functionality in its first line. It is understood that in this case the log might be transferred once again this link is always displayed even if the log cannot be loaded.
• The History View and the history as visible from the Jobs View, Job Chains View and Orders View receive a "Download" icon for each history entry. The icon is displayed before the Order ID or Task ID of a history entry.

Maintainer Note

• New APIs are introduced
  • ./task/log/download
  • ./order/log/download