soffice: Implement methods for status bar announcement (#14933)
Fixes #11698
Summary of the issue:
Announcement of the status bar in LibreOffice (e.g. triggered by NVDA+End) didn't work because the default implementations do not work for the LibreOffice case.
Description of user facing changes
Announcement of the status bar (e.g. triggered
by NVDA+End) works for LibreOffice.
Description of development approach
Override the default app module implementation to retrieve the status bar and announce its text in the LibreOffice app module, since the default implementations are not sufficient for the LibreOffice case:
To retrieve the status bar object, locate the descendant with the corresponding role, but only descend into children of role ROOTPANE and WINDOW for performance reasons.
To generate text from the status bar object, retrieve the text of each status bar child using the IAccessibleText interface. (The default implementation in api.py only uses the object names and values, which are both empty.)
