Add tunnel timeout for ui proxy container

Add tunnel timeout for ui proxy container

Add an explicit tunnel timeout configuration option to increase the
tunnel timeout for persistent socket connections from two minutes (2m)
to one hour (3600s).  A configuration was already present to apply a
tunnel timeout to the zaqar_ws endpoint, but that only applies to
connections made directly to the zaqar_ws endpoint directly.  Since UI
now uses mod_proxy to proxy WebSocket connections for Zaqar, the timeout
is now applied for the same reasons to the ui haproxy server.

Change-Id: If749dc9148ccf8f2fa12b56b6ed6740f42e65aeb
Closes-Bug: 1672826