Aligned CD train-test functionality

[KulikDM]

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This PR addresses the issue of predicting on test data.

I have noticed that some outlier methods do not correctly apply their methods to test data. They simply fix a new OD to the test data instead of evaluating it against the fitted OD on the train data. CD was one such case, and this PR has rectified the issue with minimal changes.

In the future, I will investigate the other OD methods that have this issue to try and align them in this manner too.

[coveralls]

Pull Request Test Coverage Report for Build 13085676475

Details

• 12 of 12 (100.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.002%) to 95.363%

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Totals
Change from base Build 12743748830:	0.002%
Covered Lines:	10366
Relevant Lines:	10870

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💛 - Coveralls