Speed up and improve integration tests

[jspdown]

What does this PR do?

This PR:

• Split the integration_test.go into 2 packages: tool and k3d
• Use dig, curl and netcat to make sure configurations work and not just dynamic config diff.
• Import all images at once with k3d
• Speed up parallel testing by pulling only the images needed in the test.
• Switch from imagePullPolicy: Always to IfNotPresent to avoid pull 2 times images.
• Use SMI CRDs defined in the Helm chart instead of the copy made in testdata.
• Improved logging, added a --debug option.
• CoreDNSSuite & KubeDNSSuite:
  • Don't start a controller, just create a fake shadow service
  • For every supported versions, try to resolve a .mesh address
  • Remove unsupported versions (CoreDNS 1.2.6)
• ACLDisabledSuite & ACLEnabledSuite:
  • Deploy a controller and a proxy once and for all
  • Use curl to make sure if we can reach or not the different servers.
  • Added more test to make sure we correctly support header and path filtering on TrafficTargets

Fixes: #615

How to test it

• make test-integration TESTFLAGS="--debug"

Additional Notes

This PR is currently blocked by #710