Rename Home Assistant value_template to state_value_template

[adamkoch]

In Home Assistant value_template is deprecated and replaced by state_value_template as of HA 2022.02.x.

This breaks devices from working in Home Assistant when using Home Assistant's MQTT Discovery: https://github.com/home-assistant/core/issues/65739

I couldn't find where this deprecation is announced but other plugins are having similar issues: https://github.com/home-assistant/core/issues/65881#issuecomment-1030850526

I tested this myself and it fixes up the issues.

[xAPPO]

Thanks for this Adam - I missed it too I am about to release beta 3e and will apply this fix to that.

Most people are already running this later version .. surprised you're not ?

[adamkoch]

Most people are already running this later version .. surprised you're not ?

Ah didn't realise there was a beta 3e! I haven't been paying attention to the latest recently but just noticed this issue because it broke a bunch of my lights :) You can close this PR if you need to apply it to your own branch.