f068b3bf5c
In the case where the bufferlist is writable, send the buffers immediately without adding to the refcount. This allows writable buffers to maintain their writability, even without implementing a chain_list function on the element. Adds a test to verify this property, where a writable list maintains refcount 1, but a readonly list increases it. Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/7894>