Add test for admin_es_cmds part I

[bowenxia]

What changed?

• Add test for admin_es_cmds part I.
• Also, when refactoring admin_es_cmds, there are failures in admin_cluster_cmds_test, I've made some refactor in that files as well to not fail tests. But there are some more fmt.println() usages in AdminRebalanceList -> ListWorkflow -> displayPagedWorkflows that needs to be refactored. This change will require workflow_commands_tests.go to be refactored as well. So I'll do this in next PR.

Why?
for a better code coverage

How did you test it?
unit test

Potential risks

Release notes

Documentation Changes

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 76.40%. Comparing base (a2451be) to head (947b63a).
Report is 3 commits behind head on master.

Additional details and impacted files

Files with missing lines	Coverage Δ
tools/cli/render.go	87.05% <100.00%> (ø)
tools/cli/workflow_commands.go	66.93% <100.00%> (+0.01%)	⬆️

... and 7 files with indirect coverage changes

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