For local development, support multiple `actions.json` files

Based on this discussion that was opened by @bspotswood: https://github.com/orgs/codefori/discussions/2653

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We need to be able to customize actions further and per-directory. Let's look into picking up the actions file based on the URI that they user is running the action(s) against.

My simple thoughts:

* default to `.vscode/actions.json` for actions, or
* find the next `actions.json` in the parents of the working directory. For example, I am working in `src/partA/qrpglesrc/scooby.rpgle`, then first look for `src/partA/qrpglesrc/actions.json`, then `src/partA/actions.json`, and so on. This is similar to how `package.json` works with npm.

Importantly, we cannot break the current experience, so this should be in addition to what currently works for local development.