* moving cli helper functions to the respective packages with _helper.
* removed cmds.go within pkg/ dir and added config_helper.go
* In the first commit(https://review.opendev.org/#/c/707216/) commit CLI helper
functions were moved from the cmd/config package to the pkg/config package
* Now we are trying to move the CLI helper functions within their respective packages instead of a command cmds.go.
* Creating and implementing this convention will help us better distinguish library code and CLI helper code
* Added MaxNArgs as 1 for get-credentials and updated test cases
Relates-To: #43
Change-Id: Ibb8139102bd98c6c7596bd97377cf83381cbeb00
01d66c834d