fix: trim whitespace bug

[CloudBeard]

Description

Trimming the whitespace in the addPart function fixes the format issues in the bug below.

It did create a new issue with indenting nested assessment objectives so added the quick fix for that.

Related Issue

Fixes # #676

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

[brandtkeller]

Tested changes with:

./bin/lula generate component -c https://raw.githubusercontent.com/usnistgov/oscal-content/master/nist.gov/SP800-53/rev5/json/NIST_SP-800-53_rev5_catalog.json -r ac-1,ac-2,ac-3,ac-3.2,ac-4 -o oscal-component.yaml --remarks assessment-objective

And seeing ac-2 remarks being generated properly.

I don't see a discernible difference between the loop syntax but have no issues with the change either.