* Add support for payload_template in rest component
* Update homeassistant/components/rest/schema.py
* Update homeassistant/components/rest/data.py
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Co-authored-by: Erik Montnemery <erik@montnemery.com>
* Use CONF_CORE to reference `homeassistant` domain
* Just use DOMAIN
* USE DOMAIN for `homeasistant` domain in config_schema.py
* Use DOMAIN_HA as constant for homeassistant domain
* Rename CONF_CORE to DOMAIN_HA
* Rename DOMAIN_HA to HA_DOMAIN
* Use relative import
* Use direct imports