WP_HTTP_Response: Use setter instead of directly accessing the $data property

[tfrommen]

The constructor of the WP_HTTP_Response class (and thus also WP_REST_Response) has three arguments: $data, $status and $headers.

While there is a dedicated setter for each of the three properties, $data is set directly.

In order to enable people to rely on inheritane and automatically use overwritten methods, let's use the setter, please.

Patch will follow soonish.

[SergeyBiryukov]

In 41707:

HTTP API: Use WP_HTTP_Response::set_data() in ::__construct() instead of directly accessing the $data property.

Props tfrommen.
Fixes #41759.