Stunner - Redundant download/export buttons on the toolbar

There are redundant download/export buttons on the toolbar and it is confusing from the point of view of the user.

• The first one allows the user to export the current view to different formats (image, pdf and BPMN) including changes not saved yet.
• The second one which is labeled "Download" allows the user to download versioned BPMN files. Although it is possible do load different versions of the process, changes made but not saved, are not exported to the BPMN file. This behavior is unusual for editors that generally export the current view.

The second button should be removed. This way, the user can always export the current view, even if it was loaded from a different version or changed later avoiding misconception of the functionality.

Acceptance criteria

"Download" button is removed from all Stunner based editors in business-central.
Button with drop-down list for downloading various files (png, jpg, svg, pdf and bpmn) is not removed.

• When a user select "bpmn", the file with name $FILE_NAME.bpmn is downloaded. The file contains bpmn source of the process.