Add recentsService unit tests.
Add recentsService unit tests.

matrix-org/synapse,howethomas/synapse,howethomas/synapse,rzr/synapse,matrix-org/synapse,TribeMedia/synapse,rzr/synapse,illicitonion/synapse,howethomas/synapse,illicitonion/synapse,matrix-org/synapse,illicitonion/synapse,TribeMedia/synapse,matrix-org/synapse,howethomas/synapse,illicitonion/synapse,TribeMedia/synapse,matrix-org/synapse,howethomas/synapse,rzr/synapse,TribeMedia/synapse,rzr/synapse,illicitonion/synapse,TribeMedia/synapse,iot-factory/synapse,iot-factory/synapse,matrix-org/synapse,iot-factory/synapse,iot-factory/synapse,iot-factory/synapse,rzr/synapse