Resolves #1368

Changes proposed in this PR:

• Remove most files in idaes/core/dmf
• Edit idaes/core/dmf/__init__.py to add deprecation to be shown when importing idaes.core.dmf
• Trim logic used to skip tests that need optional dependencies
• Remove code that was only used for DMF from setup.py
• Remove dmf_data directory

To review

• Check if the (very minimal) deprecation infrastructure is OK (@andrewlee94?)
• Check if the pages that have been modified in the docs make sense:
  • https://idaes-pse--1484.org.readthedocs.build/en/1484/how_to_guides/opt_dependencies.html
  • https://idaes-pse--1484.org.readthedocs.build/en/1484/how_to_guides/workflow/data_rec_parmest.html
• See if you spot any mention of the DMF in the code without a comment/deprecation or something like that

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