Remove use of deprecated default rec rule settings

from MythWeb.  These values should all be set from the recording rule
templates.  Fixes #11138.  Refs #11512.

Backporting to 0.26 since there is no way to set the values being used
by MythWeb in 0.26.
(cherry picked from commit 71ee4dd6692a6ae9d99f9626459868f9863e30dc)
Use Default recording rule template in MythWeb

when creating new recording rules.  This patch only uses values from the
Default recording rule template, but it's still better/more capable than
the old approach that pulled values for a few parameters from settings.

Patch by Paul Gardiner (thanks!) with minor changes by me.
Fixes #11512.

Signed-off-by: Michael T. Dean <mdean@mythtv.org>

Backporting to 0.26 since users who upgraded from previous versions of
MythTV (and, therefore, had set the no-longer-existing settings) were
relying on their effect.  This provides a functional replacement that
uses the proper approach for current MythTV.
(cherry picked from commit f97529656ca2e7e4aa7806eb493873d72b2b7cef)