fix(kubevela): split vela-cli into its own subpackage

[tulilirockz]

That way we dont need to have the entire vela-cli when installing the kubevela operator (vela-core).
Saves about 40MB when you just want the operator

I'm not how to approach this tho, should it be an entirely separate package or just a subpackage here?

[jamonation]

Let's figure out how to refactor the subpackage/package dependencies to ensure apk add kubevela gets the CLI version

[tulilirockz]

Split the package into vela-core + vela-cli now and a depends for the kubevela, that way we have the same functionality for kubevela and we can install them separately if we want to. (As @jamonation suggested)