Find where context menus should appear

Analyze EiffelStudio for places where one expect a context menu to appear. Currently it is mostly where one can start a pick and drop, but it could also be in some other areas (e.g. the context menu of the editor to display editing commands).

Currently 2 test cases reflect that list:

• tcs#22: Location where a pick and drop or a context menu would appear depending on your preferences.
• : Location of known context menus