Create Snapshot fix: Get isiPath from source volume's export path

[santhoshatdell]

Description

For the CreateSnapshot call, the required isiPath is now retrieved from the source volume's export path like it is done in the replication code. So, there will be no need to get PV's 'Path' value or remove any prefix. Hence, reverting the changes made in previous PRs #355 and #383

Related PRs:
dell/csm-operator#1012
dell/helm-charts#753
dell/csm-docs#1573

GitHub Issues

List the GitHub issues impacted by this PR:

GitHub Issue #
dell/csm#1920

Checklist:

• I have performed a self-review of my own code to ensure there are no formatting, vetting, linting, or security issues
• I have verified that new and existing unit tests pass locally with my changes
• I have not allowed coverage numbers to degenerate
• I have maintained at least 90% code coverage
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• Backward compatibility is not broken

How Has This Been Tested?

• Create snapshot with "volume-name-prefix=csivol" (default).
• Create snapshot with "volume-name-prefix=k8s".
• Create snapshot for volume created earlier with different prefix.
• Create snapshot for replicated PV.
• Create snapshot for volume with Authorization module enabled.
• cert-csi tests have passed for driver.
• Auth E2E tests for Volume & Snapshot have passed.

Logs are attached to the internal ticket ECS01E-526.

[github-actions]

Merging this branch will not change overall coverage

Impacted Packages	Coverage Δ	🤖
github.com/dell/csi-powerscale/common/constants	0.00% (ø)
github.com/dell/csi-powerscale/common/utils	0.00% (ø)
github.com/dell/csi-powerscale/service	0.00% (ø)

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Coverage by file

Changed files (no unit tests)

Changed File	Coverage Δ	Total	Covered	Missed	🤖
github.com/dell/csi-powerscale/common/constants/consts.go	0.00% (ø)	0	0	0
github.com/dell/csi-powerscale/common/constants/envvars.go	0.00% (ø)	0	0	0
github.com/dell/csi-powerscale/common/utils/utils.go	0.00% (ø)	0	0	0
github.com/dell/csi-powerscale/service/controller.go	0.00% (ø)	0	0	0
github.com/dell/csi-powerscale/service/service.go	0.00% (ø)	0	0	0

Please note that the "Total", "Covered", and "Missed" counts above refer to code statements instead of lines of code. The value in brackets refers to the test coverage of that file in the old version of the code.

Changed unit test files

• github.com/dell/csi-powerscale/common/utils/utils_test.go
• github.com/dell/csi-powerscale/service/service_test.go
• github.com/dell/csi-powerscale/service/step_defs_test.go