Display issues on Field Note overview example

[fabriciomurta]

The major display issue here is related to field notes and chrome 56 (and possibly newer). The related issue to this specific glitch is extnet/Ext.NET#1428. And the fix here should be reverted as soon as the parent issue is solved.

Additional issues with the formPanel not fitting on specific themes are also addressed here by issuing specific width/height values depending on the active theme.