Add a centralised concept for using / retrieving data from current edition’s collection

[bwbohl]

This issue serves as a collection point for issues dealing with data from the active entity collection. Please feel free to add the respective issues as tasks below.

Several issues are open around some XQueries that use a wrong database path to retrieve data relevant to the activeEdition. Instead of creating individual fixes in those queries, we should centrally define a function for retrieving data from the activeEdition context and use it where applicable.

• getAnnotationsOnPage.xql could return "wrong" data. #83
• SearchWindow: Use edition path for collection function #156
• getAnnotationsInText.xql should search edition collection #240