* De-share the Handler struct in core API
An upcoming PR adds a handler that only applies on one of these paths.
Having fields that don't work seems bad.
This never should have been shared. Lifecycle hooks are like a "write"
while probes are more like a "read". HTTPGet and TCPSocket don't really
make sense as lifecycle hooks (but I can't take that back). When we add
gRPC, it is EXPLICITLY a health check (defined by gRPC) not an arbitrary
RPC - so a probe makes sense but a hook does not.
In the future I can also see adding lifecycle hooks that don't make
sense as probes. E.g. 'sleep' is a common lifecycle request. The only
option is `exec`, which requires having a sleep binary in your image.
* Run update scripts
The "[Feature:SCTP]" tag was needed on "should not allow access by TCP
when a policy specifies only SCTP" back when SCTP was alpha, because
it wasn't possible to create a policy that even mentioned SCTP without
enabling the feature gate. This no longer applies, and the tag was
removed from the original copy of network_policy.go, but accidentally
got left behind in the netpol/ version.
Likewise, the newly-added "should not allow access by TCP when a
policy specifies only UDP" got tagged "[Feature:UDP]", but this was
never necessary, and is inconsistent with other UDP tests anyway.
Similarly, we need "[Feature:SCTPConnectivity]" on tests that make
SCTP connections, because that functionality is not available in all
clusters, but "[Feature:UDPConnectivity]" is unnecessary and
inconsistent.
