Fuse routes editor should not be in "open with" list for switchyard.xml files

"Fuse Tooling Routes Editor" is listed in "Open With" list for switchyard.xml files. The routes editor should be constrained to applicable files.

Steps to reproduce:
1. Create a SwitchYard project
2. right-click switchyard.xml file in navigator and select "Open With"

Notice Fuse Tooling Routes Editor is in the list. If you click on this, it spins for a while then an editor with an empty canvas is opened.