Enable spinning up only a subset of an application's components

[kate-goldenring]

Summary

Say I have an app with 4 components but only want to run 2, I should be able to do the equivalent of spin up --component "foo" --component "bar"

Background

Spin unifies serverless application development. Developers can define distinct functions as components and group them all together into one fully-featured Spin application. Each of these components has unique requirements, such as access to a database or LLM. Not all of these requirements are always available to the developer or in production. For these reasons, developers should be able to run a subset of components of a Spin application.

Proposed DevX

# Run all components 
spin up
# Run the `hello-rust` and `hello-go` components
spin up --component "hello-rust" --component "hello-go"

[kate-goldenring]

I am working on a SIP for this

[kate-goldenring]

The scope of this is too small to deem a SIP necessary. I am adding more context on the design to this issue instead