ostree-fetcher: drop _ostree_fetcher_contents_membuf_sync unused argument user_data

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
ostree-repo-pull: rename some functions

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
ostree-fetcher: add max_size argument to change _ostree_metalink_request_sync

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
ostree-metalink: use _ostree_fetcher_request_uri_to_membuf

It replaces usage of _ostree_fetcher_request_uri_to_stream.

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
ostree-fetcher: Remove _ostree_fetcher_request_uri_to_stream function

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>