[Enhancement] Better status message when adding existing repo

- Avoids Blocking UI When Adding Existing Repo

Closes borgbase#1306

src/vorta/views/repo_add_dialog.py

@@ -242,10 +242,10 @@ def run(self):
             params = BorgInfoRepoJob.prepare(self.values)
             if params['ok']:
                 self.saveButton.setEnabled(False)
-                thread = BorgInfoRepoJob(params['cmd'], params)
-                thread.updated.connect(self._set_status)
-                thread.result.connect(self.run_result)
-                self.thread = thread  # Needs to be connected to self for tests to work.
-                self.thread.run()
+                job = BorgInfoRepoJob(params['cmd'], params)
+                job.updated.connect(self._set_status)
+                job.result.connect(self.run_result)
+                self.job = job  # Needs to be connected to self for tests to work.
+                QApplication.instance().jobs_manager.add_job(job)
             else:
                 self._set_status(params['message'])