[568326] Reworked boot file wizard for new project layout

this fix adds a dedicated system selection widget to the boot file
wizard. This fixes the problem of the empty device list.

Furthermore also the FMU export has been updated to the new exporter
reducing some code duplication.

Bug: https://bugs.eclipse.org/bugs/show_bug.cgi?id=568326
Change-Id: I7ce11a75ff41bb897c9b41fe4f8af46e2f5371d9
11 files changed