NewTools-FileBrowser should not use StInspector but switch to StObjectInspectorPresenter

[astares]

The package "NewTools-FileBrowser" creates an extension on StInspector which is a deprecated class in Spec2 now.
The method provided as extension is StInspector class>>#instanciateOn:

There is only a single sender StFBInspectPreviewer>>#previewActionOn: of this method #instanciateOn:
that we can adopt from:

previewActionOn: aFileReference
	^ StInspector instanciateOn: aFileReference

to

previewActionOn: aFileReference
	^ StObjectInspectorPresenter onObject: aFileReference

to use StObjectInspectorPresenter instead of the deprecated StInspector class.