Fail vs. fatal on store startup (#24170)

If the store fails to initialize (e.g. run a migration), it would `log.Fatal` and then `os.Exit`. Unfortunately, this trips up `TestMain`, which happily keeps running tests, now guaranteed to fail.

Avoid this by instead returning an error from the store initialization, handling appropriately at the layer above.

server/platform/services/searchengine/bleveengine/bleve_test.go

@@ -49,7 +49,12 @@ func (s *BleveEngineTestSuite) setupStore() {
 		driverName = model.DatabaseDriverPostgres
 	}
 	s.SQLSettings = storetest.MakeSqlSettings(driverName, false)
-	s.SQLStore = sqlstore.New(*s.SQLSettings, nil)
+
+	var err error
+	s.SQLStore, err = sqlstore.New(*s.SQLSettings, nil)
+	if err != nil {
+		s.Require().FailNow("Cannot initialize store: %s", err.Error())
+	}
 
 	cfg := &model.Config{}
 	cfg.SetDefaults()