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

[worksofliam]

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

---

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.

[worksofliam]

I am thinking we need a simple function like resolveActionsForUris(uris: Uri[]): Action[]