feat(template): enable remote file templating

[brandtkeller]

Description

The purpose behind this change is to experiment with some workflows we could adopt for use with centralized oscal templates.

Use the network package for fetching files (local or remote)

Add helpers for uuid and timestamp in the go templating funcmap.

Testing

I created this templates repository to house a templated-remote component-definition containing our baseline controls. This is a prototype repo - we can move the future artifacts somewhere permanent in the future.

Copy the lula-config.yaml locally and execute:

./bin/lula tools template -f https://raw.githubusercontent.com/brandtkeller/templates/refs/heads/main/component.yaml

Related Issue

No related issue currently

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Other (security config, docs update, etc)

Checklist before merging

• [] Test, docs, adr added or updated as needed
• Schema Updates applied
• Contributor Guide Steps followed