Regression from commit 63ff8602.
See thread started at
  https://lists.freedesktop.org/archives/libreoffice/2018-December/081542.html

The Application::SetName is mandatory for DDE to work; otherwise
InitializeDde() in SfxApplication::SfxApplication() fails.

DDE spreadsheet formula expects full name of the target spreadsheet,
including path.

Fixed sheet name (it's "Sheet1", not "Sheet").

Removed redundant tests (former "testRemoveRefreshListener" tests all).

Change-Id: I6299a9ec03c3657a21ad42d0ff87db25cf2be905
Reviewed-on: https://gerrit.libreoffice.org/65079
Tested-by: Jenkins
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>