Duplicate controls when importing from resolved profile

[selenaxiao-nist]

Cloning usnistgov/oscal-cli#315
ProfileResolver doesn't resolve profiles correctly in the following case:

Describe the bug

A produced profile can have multiple copies of controls

When does this occur?

When importing from a resolved profile.

How do we replicate the issue?

The specific steps I used to find this issue were:

1. oscal-cli profile resolve --to=xml liboscal-java/src/test/resources/content/test-oscal-version-profile.xml source-profile.xml
2. Create another profile (say, derived-profile.xml)
3. Have <import href="source-profile.xml> <include-all /> </import> inside derived-profile.xml
4. oscal-cli profile resolve --to=xml derived-profile.xml
5. Lo and behold, the generated profile has duplicates of the controls in it

source-profile.xml
derived-profile.xml

Expected behavior (i.e. solution)

Only one set of controls from the imported profile in the resolved profile