ref #6925 Set conversation and cdmEntitySession to null for dispose
ref #6925 Open PK editor in editor area
ref #6908 Avoid opening the same PK in multiple editors
ref #6908 Close PK editor when deleting key
ref #6925 Inject context into operations to allow sync/async execution
ref #6908 Migrate remaining polytomous context menus and handlers
ref #6908 Migrate polytomous key list editor handlers
ref #6908 Migrate polytomous key list editor