ci: Check all paths in ciliumHealthPreFlightCheck
ci: Check all paths in ciliumHealthPreFlightCheck

In our CI setup, we have a helper function called
`ciliumHealthPreFlightCheck` which ensures that all nodes participating
in CI have connectivity to each other. However, that check did not
consider connectivity to remote endpoints or alternative paths.

This commit extends that function to ensure that not only connectivity
between the node has been established, but also that connectivity to the
health endpoint both via ICMP and HTTP is healthy.

This commit also introduces checks for secondary addresses (i.e. IPv6
addresses in dual-stack setups). If no secondary addresses are present,
the JSONPath filter used here returns an empty string which will be
ignored.

Signed-off-by: Sebastian Wicki <db043b2055cb3a47b2eb0b5aebf4e114a8c24a5a@isovalent.com>

michi-covalent/cilium,cilium/cilium,michi-covalent/cilium,michi-covalent/cilium,cilium/cilium,cilium/cilium,cilium/cilium,michi-covalent/cilium,cilium/cilium,michi-covalent/cilium