Fix package plugin tests for classy clusters

[shyaamsn]

What this PR does / why we need it

Fix package plugin tests for classy clusters. Classy clusters use packageInstall CR on management cluster for installing kapp-controller on workload cluster. Legacy clusters use App CR on management cluster for installing kapp-controller on workload cluster. In the test we were pausing App before patching kapp-controller configmap but in Classy clusters this was getting overridden since PackageInstall CR is not paused. This change makes sure to check if packageinstall is found then pause packageinstall else pause app.

Which issue(s) this PR fixes

Fixes #4209

Describe testing done for PR

Ran the test on a classy and legacy cluster and it passes

Release note

Fix package plugin tests for classy clusters

Additional information

Special notes for your reviewer

[codecov]

Codecov Report

Merging #4192 (27f2e6c) into main (6b5fb26) will decrease coverage by 0.84%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #4192      +/-   ##
==========================================
- Coverage   49.27%   48.42%   -0.85%     
==========================================
  Files         450      480      +30     
  Lines       44575    46697    +2122     
==========================================
+ Hits        21963    22612     +649     
- Misses      20533    21960    +1427     
- Partials     2079     2125      +46     

Impacted Files	Coverage Δ
cmd/cli/plugin/cluster/set_node_pool.go	14.63% <0.00%> (ø)
cmd/cli/plugin/cluster/available_upgrade.go	16.32% <0.00%> (ø)
cmd/cli/plugin/cluster/get_machinehealthcheck.go	11.42% <0.00%> (ø)
cmd/cli/plugin/cluster/list.go	11.36% <0.00%> (ø)
cmd/cli/plugin/cluster/credentials_update.go	8.73% <0.00%> (ø)
...i/plugin/cluster/delete_machinehealthcheck_node.go	16.66% <0.00%> (ø)
cmd/cli/plugin/cluster/upgrade.go	58.94% <0.00%> (ø)
...in/cluster/get_machinehealthcheck_control_plane.go	11.11% <0.00%> (ø)
cmd/cli/plugin/cluster/set_machinehealthcheck.go	23.33% <0.00%> (ø)
...in/cluster/set_machinehealthcheck_control_plane.go	21.21% <0.00%> (ø)
... and 22 more

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