test/k8sT: Reduce code duplication in Policies suite
test/k8sT: Reduce code duplication in Policies suite

This commit makes a few changes to the Policies suite which will be
useful in the subsequent commit.

* Extract common functions from Policies suite to be used outside of the
  Describe block
* Converge existing testCurlFromOutside() usage from the Services suite

Signed-off-by: Chris Tarazi <711c73f64afdce07b7e38039a96d2224209e9a6c@isovalent.com>

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