Add a memory reference helper struct that we can use to track the memory
in buffers and formats.
Remove custom property get and set, the default ones will work fine.
Custom ones are problematic when we want to serialize properties in
formats etc.
Deserialized Formats are now tracked in the memory pool and can be freed
if needed.
Make buffer data point to a registered memory block by its mem_id.
Add some more helpers to allocate memfd backed memory.
Allocate buffers in memfd so that we easily share them between client
and server.
Update pts and seq in v4l2 now that this change will actually be visible
at the client.
Use stucture offsets instead of pointers so that we can share the buffer
structure between client and server.
We can then pass an fd wrapping the memory of the buffer to the client.
Add beginnings of a memory pool
