Prototype of publishing through a pre-created cspkg file
Extract out common routine of deploy existing package
skip loading setting file unless it does exist in the disk. This is needed to get bunches of legacy unit test pass
address a failing unit test cased by reordering storage service operations
Add new unit tests for package based cloud publish
Accept uri based package path so to enable publish from storage account directly
update command help for 2 newly added parameters
Merge pull request #2344 from yugangw-msft/PublishVSServiceProject

Add support to publish pre-created