Added org.simantics.ui.workbench.editor.input.ResourceEditorInputMatchingStrategy

Added org.simantics.ui.workbench.editor.input.ResourceEditorInputMatchingStrategy
to customize the comparisons performed by Eclipse's EditorManager when looking
for editor input matches in existing editor tabs.

Normally EditorManager matches the following data:
* IEditorInput.getName()
* IEditorInput.getPersistable().getFactoryId()
* IEditorInput.equals

With ResourceEditorInput and ResourceEditorInput2 it is not necessary to compare IEditorInput.getName, which currently causes problems since initializing a ResourceEditorInput will not initialize its name properly immediately. And anyway, it is better simply to match against input.equals since the a single resource
can only have a single name and the name stored in the editor is just redundant information. Only the input resource identification is important.

fixes #3207

git-svn-id: https://www.simantics.org/svn/simantics/sysdyn/trunk@24182 ac1ea38d-2e2b-0410-8846-a27921b304fc