In order for us to support streaming to more than one chromecast using
the same instance of libvlc (as through VLM), and with the same
options for the httpd, we will need to have a unique identifier for
each output.

These changes generates a random path upon initialization of the
relevant object, while also incorporating the current tick. There is
an extremely slim chance that two chromecast souts would try to create
the http bindings at the exact same time, but vlc_tick_now + a random
identifier is a "better safe than sorry" implementation.

In order to really dive down in the "better safe than sorry"-category,
we try three times before giving up.

fixes: #20380
fixes: #20890
Signed-off-by: Thomas Guillem <thomas@gllm.fr>