No longer override isAlive on UIA WordBrowseModeDocument (#11885)
* No longer override isAlive on WordBrowseModeDocument
* Always log an error when we couldn't update a tree interceptor
* api.setFocusObject: log the exception if there is an error updating a treeInterceptor.
Co-authored-by: Michael Curran <mick@nvaccess.org>
