* exposed content_type in rest_command, which allows for manually specifying the content_type for more-strict api endpoints
* fixed up column length
Length was 86 chars, and it needed to be 79
* double import of HTTP_HEADER_CONTENT_TYPE
Removed the accidental double-import of HTTP_HEADER_CONTENT_TYPE
* moved rest_command-specific config value into component
* if no content_type, default to None
* unit test
* newline
* unused CONTENT_TYPE_TEXT_PLAIN
* removed the http-agnostic abstraction hass provided in favor of aiohttps hdrs constant
226066eafd