It is possible that a subscripition request can occur between
after Klipper updates a field's status, but before it pushes
a status update to the connection. The result is a race
condiiton where the response to the subscription request
contains the lastest state but it is not propagated to
currently connected clients.
This is resolved by caching subscripiton data, diffing it
with the response to the subscription request, and
manually pushing the diff.
Signed-off-by: Eric Callahan <arksine.code@gmail.com>
7e85ac97c9