Add plural aliases to kpack noun subcommands

[sampeinado]

This week I saw thomas risberg from Spring Cloud Data Flow type "kp images list" and it didn't work (although the error message did suggest the correct noun!).

Some other CLIs, ex kubectl, allow the user to type plural or singular nouns and the command works either way. In order to reduce minor friction in DevOps engineers' workflows, and to make the kp cli easier to learn, I propose adding plural aliases to all the kpack noun subcommands

build -> builds builder -> builders cluster-builder -> cluster-builders image -> images secret -> secrets stack -> stacks

exceptions: store version help