Standardise error responses for the rest endpoint

[mecachisenros]

Overview

• Standardise error responses for the rest endpoint to be event with extern/rest.php, instead of returning a WP_Error we return the API Exception's extraParams.
• Adds .editorconfig file (seemed a bit overkill to open another PR just for that, but le me know if it's needed).

Before

An error (WP_Error) response would look like:

{
	"code": "civicrm_rest_api_error",
	"message": "Mandatory key(s) missing from params array: contact_type",
	"data": {
		"status": 403
	}
}

After

An error (CiviCRM_API3_Exception) looks like:

{
	"fields": [
		"contact_type"
	],
	"error_code": "mandatory_missing",
	"entity": "Contact",
	"action": "create",
	"is_error": 1,
	"error_message": "Mandatory key(s) missing from params array: contact_type"
}

Comments

For reference see mecachisenros/civicrm-wp-rest/issues/5

[christianwach]

@mecachisenros Thanks!