Slow population of available sensors in relay control/Temperature control rules #1585
Description
When enabling a relay as temperature control the resultant Temperature Control rules page is very slow to populate list of sensors when using the V2 remote GUI.
The user see's this page.
For maybe 5-7 seconds and then gets this
It would be better to provide a message such as loading and then after a period of time if there are no sensors show "No Temperature Sensors have been added yet".