mgr/nfs: add support for selecting between haproxy ingress modes

mgr/nfs: add support for selecting between haproxy ingress modes

When the haproxy-standard mode is selected, the haproxy ingress will
behave as in previous versions of ceph. When the haproxy-protocol mode
is selected, we need to enable protocol support on the ingress service
and nfs service.

While were at it, make a few organization tweaks to improve readability.

Fixes: https://tracker.ceph.com/issues/58933
Signed-off-by: John Mulligan <jmulligan@redhat.com>