Code coverage for existing unit tests

[chethanv28]

What this PR does / why we need it:
PR is adding Code coverage analysis for existing unit tests & then use the summary in make build.
As of today we have a very low overall code coverage. So, adding a check for overall code coverage does not make sense. But for the existing unit tests & any new tests that get added in the future we will have threshold of 75% coverage in amek build process itself.

The make build will execute the below steps:
✅ Compile the binaries
✅ Run unit tests with coverage
✅ Validate that tested functions have good coverage (≥75%) (For existing unit tests or any new unit tests that get added)
❌ Fail the build if code coverage drops below 75% For existing unit tests or any new unit tests that get added)

This is not a PR to increase the code coverage but intent is to introduce the code coverage analysis tool for every new check-in from now on.

We will continue to print the below summary until we reach overall coverage goal of 75~80%

Analyzing coverage quality (excluding 0% functions)...
Total functions: 1028
Functions with 0% coverage: 790 (76.8%)
Functions with >0% coverage: 238 (23.2%)
Overall coverage (including 0%): 17.7%
Quality coverage (excluding 0%): 76.6%
SUCCESS: Quality coverage 76.6% meets threshold 75.0%
NOTE: Consider adding tests for 790 untested functions to improve overall coverage.

Testing done:
$ make build

[Terminal output truncated: ~805KB dropped from beginning]
driver/v3/pkg/common/config/config.go:333:										isValidvCenterUsernameWithDomain				100.0%
sigs.k8s.io/vsphere-csi-driver/v3/pkg/common/config/config.go:343:										validateConfig							69.5%
sigs.k8s.io/vsphere-csi-driver/v3/pkg/common/config/config.go:513:										ReadConfig							0.0%
sigs.k8s.io/vsphere-csi-driver/v3/pkg/common/config/config.go:531:										GetCnsconfig							0.0%
sigs.k8s.io/vsphere-csi-driver/v3/pkg/common/config/config.go:567:										GetDefaultNetPermission						100.0%
sigs.k8s.io/vsphere-csi-driver/v3/pkg/common/config/config.go:579:										FromEnvToGC							0.0%
...
...
total:																		(statements)							17.1%
Analyzing coverage quality (excluding 0% functions)...
Total functions: 1028
Functions with 0% coverage: 793 (77.1%)
Functions with >0% coverage: 235 (22.9%)
Overall coverage (including 0%): 17.6%
Quality coverage (excluding 0%): 76.9%
SUCCESS: Quality coverage 76.9% meets threshold 75.0%
NOTE: Consider adding tests for 793 untested functions to improve overall coverage.

Special notes for your reviewer:

Release note:

Code coverage for unit tests

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: chethanv28

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[chethanv28]

/ok-to-test

[deepakkinni]

Triggering CSI-WCP Pre-checkin Pipeline for this PR... Job takes approximately an hour to complete
Jenkins Build #592

[deepakkinni]

SUCCESS --- Jenkins Build #592

[chethanv28]

/test pull-vsphere-csi-driver-verify-golangci-lint