dev/core#2769 use php email validation not hacked qf

dev/core#2769 use php email validation not hacked qf

Per https://lab.civicrm.org/dev/core/-/issues/2769 we have had problems over the years with
quickform's email validation and we now have a hacked version that is
problematic from a maintenance pov & also doesn't work
with the string I have just encountered: name.-o-.i.10@example.com
(which I am told is valid and which passes the php filter).

We already have an email rule which calls a php native function
which is better maintained than our layers of hacks. This
PR registers our email rule - which overrides the quickform
one. If we merge this we can revert quickform back to
unhacked which will improve debugging
and maintenance (although it's actually bypassed
now with this change)