fix(cf-macro): allow functions with no Metadata (#99)

[eoinsha]

Fix #99 , ensuring functions with no Metadata can be processed with SLIC Watch config defaults

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING.md document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[coveralls]

Coverage remained the same at 100.0% when pulling 70df80a on fix-no-metadata-in-macro-functions into 064d10f on main.