[FEATURE] Enable users to supply a package.json for a workflow

**Describe the solution you'd like**
I would like to provide a package.json and package-lock.json file with the following behavior:
- If `package.json` is supplied: Pipedream should install the NPM packages exactly as specified in my `package.json` file (equivalent to running npm install).
- If `package-lock.json` is supplied: Pipedream should install the NPM packages precisely as locked in my `package-lock.json` file (equivalent to running npm ci).

If I supply `package.json` or `package-lock.json`, I don't want Pipedream to automatically install latest packages from the `import` declarations in my Node.js steps.