Update NGCC SOEC example for new costing methods

[bpaul4]

Fixes # .

Proposed changes:

• Re-runs notebook to remove warnings currently visible in GitHub version of example
• Updates costing to use new power plant costing methods
• Note: this will work once https://github.com/IDAES/idaes-pse/pull/978 is merged, and this PR should be merged ASAP afterwards since the new methods will break the existing notebook
• The head was temporarily changed to 978 to test the example and should be reverted to main once 978 is merged.

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[bpaul4]

Until the new power plant costing methods are merged, the expected outcome when using the main idaes-pse branch is that only the NGCC SOEC example fails (due to an ImportError).

[lbianchi-lbl]

@bpaul4 I've created a "quick-n-dirty" wiki page on how to set a custom idaes-pse branch for an examples-pse PR: https://github.com/IDAES/examples-pse/wiki/howto-custom-idaes-pse. Feel free to take a look and edit it directly with any corrections or improvements.