fix issue with querying for GVR in capabilities discovery package

[yharish991]

What this PR does / why we need it

When querying for existence of GVR without version, capabilities discovery package returns false even though the resource exists. This PR is for fixing that issue.

Which issue(s) this PR fixes

Fixes #

Describe testing done for PR

Verified that the units tests are passing and wrote a small sample program to test GVR query functionality

Release note

Fixed query GVR functionality when a version is not provided in capabilities discovery package.

Additional information

Special notes for your reviewer

[codegold79]

Thanks for finding this bug and fixing it so quickly, @yharish991.

[github-actions]

Cluster Generation A/B Results:
https://storage.googleapis.com/tkg-clustergen/4272/20230111235059/clustergen.diff.txt
Author/reviewers:
Please review to verify that the effects on the generated cluster configurations are exactly what the PR intended, and give a thumbs-up if so.

[codecov]

Codecov Report

Merging #4272 (87d3b83) into main (f39341f) will decrease coverage by 0.90%.
The diff coverage is 92.30%.

@@            Coverage Diff             @@
##             main    #4272      +/-   ##
==========================================
- Coverage   49.40%   48.50%   -0.91%     
==========================================
  Files         451      481      +30     
  Lines       44755    46878    +2123     
==========================================
+ Hits        22111    22737     +626     
- Misses      20560    22004    +1444     
- Partials     2084     2137      +53     

Impacted Files	Coverage Δ
capabilities/client/pkg/discovery/cluster_gvr.go	83.60% <92.30%> (-0.84%)	⬇️
addons/controllers/machine_controller.go	65.65% <0.00%> (-3.04%)	⬇️
...ons/controllers/packageinstallstatus_controller.go	79.15% <0.00%> (ø)
.../cli/plugin/cluster/get_machinehealthcheck_node.go	9.30% <0.00%> (ø)
cmd/cli/plugin/isolated-cluster/test/main.go	0.00% <0.00%> (ø)
cmd/cli/plugin/cluster/scale.go	17.85% <0.00%> (ø)
...olated-cluster/imagepushop/publishimagesfromtar.go	73.17% <0.00%> (ø)
cmd/cli/plugin/cluster/create.go	42.22% <0.00%> (ø)
.../isolated-cluster/imgpkginterface/client_imgpkg.go	0.00% <0.00%> (ø)
... and 25 more

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

[danniel1205]

the changes lgtm, adding my approval. (But we still need to cleanup before merge)

[github-actions]

Cluster Generation A/B Results:
https://storage.googleapis.com/tkg-clustergen/4272/20230112011500/clustergen.diff.txt
Author/reviewers:
Please review to verify that the effects on the generated cluster configurations are exactly what the PR intended, and give a thumbs-up if so.

[rajathagasthya]

LGTM, thanks! Please add some tests in a follow up PR.