Replace Alias with Softlink For IBM Cloud CLI ic Short Cut

[archerzz]

Summary

We should consider use soft link for ic of IBM Cloud CLI, because it will create prompt messages which are easier for users to understand.

Steps to reproduce
(include tooling version, platform, etc)

1. Type a command which doesn't exist, like ic not-found
2. The error message will be like:

FAILED
'not-found' is not a registered command. See 'ibmcloud help'.

It would be better to show See 'ic help'. CLI prints ibmcloud here because ic is an alias which will be interpreted before passing to OS. Softlink won't have this problem.

Operating System
Specify: macOS/Linux

Supporting details
See the original issue report here: https://github.ibm.com/Bluemix/bluemix-cli/issues/2759

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Development "done" checklist

• Test case to verify
• Public Documentation updated
• Change added to "release notes" as appropropriate
• Notification to stakeholders (OM, other squads, etc)