bugfix #1706 fix PhaseDiagram use case to avoid writing into INPUT_BASE

[georgemccabe]

Corresponding PR for develop is #1708

Pull Request Testing

• Describe testing already performed for these changes:
  

Ran PhaseDiagram use case that previously failed locally if INPUT_BASE is not writable by the user and confirmed that it now works.

• Recommend testing for the reviewer(s) to perform, including the location of input datasets, and any additional instructions:
  

Confirm that changes look OK and that all automated tests pass except the diff for the new output file that is now written by the use case in OUTPUT_BASE

• Do these changes include sufficient documentation updates, ensuring that no errors or warnings exist in the build of the documentation? [Yes]

• Do these changes include sufficient testing updates? [Yes]

• Will this PR result in changes to the test suite? [Yes]
  
  If yes, describe the new output and/or changes to the existing output:
  
  The time_list_lead000.txt may flag a difference since it is now written into OUTPUT_BASE

• Please complete this pull request review by 7/26/2022.
  

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[CPKalb]

Tested and ran as expected