2021.5.0b8

• Guard logbook assuming entity ID is a string (@balloob - #50047)
• Handle missing transport_state on media update in sonos (@bdraco - #50051)
• Fix KNX climate unque_id (@farmio - #50054)
• Catch Shelly set state exceptions when device is inaccessible (@thecode - #50064)
• Update frontend to 20210504.0 (@bramkragten - #50093)