Flowgraph fixes

[bdngo]

This PR fixes several small bugs with the flowgraph frontend:

• If required output is set to -output-full.json (like in Makefiles), it overwrites the full db with that of -output.json (reduced)
• Child nodes’ required inputs get overridden by auto-inserted X-to-Y output, but we need to be able to have additional inputs

Related PRs / Issues

Type of change:

• [x] Bug fix
• [ ] New feature
• [ ] Other enhancement

Impact:

• [x] Change to core Hammer
• [ ] Change to a Hammer plugin
• [ ] Other

Contributor Checklist:

• [x] Did you set master as the base branch?
• [x] Did you state the type-of-change/impact?
• [x] Did you delete any extraneous prints/debugging code?
• [x] (If applicable) Did you add documentation for the feature?
• [ ] (If applicable) Did you update the poetry.lock file if you updated the requirements in pyproject.toml?
• [ ] (If applicable) Did you add a unit test demonstrating the PR?
• [ ] (If applicable) Did you run this through the e2e integration tests?
• [ ] (If applicable) Did you update the submodules in e2e/ if this feature depends on updated plugins?