soup-message: make soup_message_disables_feature_by_type() public

Renamed as soup_message_is_feature_disabled(). We need this in WebKit to
check if cookies are available in an existing SoupMessage.
1 job for master in 1 minute and 1 second (queued for 1 second)
Status Job ID Name Coverage
  Test
passed #801219
ipv6
fedora-meson-x86_64

00:01:01