This patch removes the IPC endpoint numbers that needed to be specified
in the IPC files. Since the string hash is a (hopefully) collision free
number that depends on the name of the endpoint, we now use that
instead. :^)
The PIDs were used for sharing shbufs between processes, but now that
we have migrated to file descriptor passing, we no longer need to know
the PID of the other side.
The ImageDecoder service now returns a list of image frames, each with
a duration value.
The code for in-process image decoding is removed from LibWeb, an all
image decode requests are sent out-of-process to ImageDecoder. :^)
This won't scale super well to very long and/or large animations, but
we can work on improving that separately. The main goal here is simply
to stop doing any image decoding inside LibWeb.
Fixes#5165.
