vulkan: add source pipeline stage to _operation_add_frame_barrier()

Instead of dragging the last destination pipeline stage as current barrier source pipeline stage (which isn't a valid semantic) this patch adds a parameter to gst_vulkan_operation_add_frame_barrier() to set the source pipeline stage to define the barrier.

The previous logic brought problems particularly with queue transfers, when the new queue doesn't support the stage set during a previous operation in a different queue.

Now the operation API is closer to Vulkan semantics.

This MR supersede !7159 (closed) and other previous changes which were workarounds.

Depends on !7200 (merged)