Fix an issue when generating ExternalEntity from ExternalNode

[wenyingd]

1. Use group/apiversion for OwnerReference when creating ExternalEntity from ExternalNode
2. Add unit tests for ExternalNodeController

Signed-off-by: wenyingd [email protected]

[codecov[bot]]

Codecov Report

Merging #4259 (944620d) into main (b2ba248) will decrease coverage by 1.68%. The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #4259      +/-   ##
==========================================
- Coverage   61.30%   59.61%   -1.69%     
==========================================
  Files         388      378      -10     
  Lines       55145    54682     -463     
==========================================
- Hits        33806    32601    -1205     
- Misses      18799    19621     +822     
+ Partials     2540     2460      -80     

Flag	Coverage Δ
e2e-tests	39.47% <0.00%> (?)
integration-tests	34.39% <ø> (-0.03%)	:arrow_down:
kind-e2e-tests	47.56% <0.00%> (+4.92%)	:arrow_up:
unit-tests	44.59% <100.00%> (-0.45%)	:arrow_down:

Impacted Files	Coverage Δ
pkg/controller/externalnode/controller.go	66.16% <100.00%> (+66.16%)	:arrow_up:
pkg/ipfix/ipfix_intermediate.go	0.00% <0.00%> (-90.91%)	:arrow_down:
pkg/ipfix/ipfix_collector.go	0.00% <0.00%> (-83.34%)	:arrow_down:
...trollers/multicluster/label_identity_controller.go	0.00% <0.00%> (-81.73%)	:arrow_down:
pkg/cni/client.go	0.00% <0.00%> (-77.78%)	:arrow_down:
pkg/flowaggregator/certificate.go	0.00% <0.00%> (-75.53%)	:arrow_down:
...rs/multicluster/commonarea/clusterinfo_importer.go	0.00% <0.00%> (-74.51%)	:arrow_down:
...s/multicluster/label_identity_export_controller.go	0.00% <0.00%> (-72.93%)	:arrow_down:
pkg/flowaggregator/exporter/utils.go	0.00% <0.00%> (-72.73%)	:arrow_down:
...kg/agent/flowexporter/connections/conntrack_ovs.go	0.00% <0.00%> (-70.91%)	:arrow_down:
... and 106 more

[wenyingd]

/test-all

[tnqn]

The unit test failure is a known issue on main branch: https://github.com/antrea-io/antrea/issues/4294, no need to rerun.