Detect inputs to a put step

[clarafu]

With #1202 implemented, it is sort of redundant to need to type out all the artifact inputs to a put step while they "most likely" have already written out the artifacts that are needed in the params. The only case we can think of for now that would not have the artifacts specified in the put params is when you would use a wildcard, which is covered by the "all" option for the inputs to a put configuration.

We can add a "detect" option to the input configuration for a put step that will go through the params and grab out a list of all the artifacts that were specified within it and use those as the inputs. It might look something like this:

- get: some-repo
- put: some-resource
  inputs: detect
  params:
    doesnt_matter: some-repo/hello

In this example we would take the some-repo from some-repo/hello and deduce that some-repo is an artifact to pull in as an input. This won't always correspond to an artifact, and in that case it should just be skipped. Note that the value some-repo should also be used to look up an artifact.