Adds ONNX Surrogate support from OMLT

[avdudchenko]

Fixes

This adds ONNX surrogate model object and slightly refactors the current Keras surrogate model to support multiple omlt model types.

Summary/Motivation:

Currently, if one generates a NN model using PyTorch, or any other method for use in IDAES and depended project (e.g. WaterTAP) we must export the model to ONNX format, and then to keras format to use in IDAES, which makes little sense.

This PR adds native support to onnx model format provided through OMLT.

Changes proposed in this PR:

-move out part of Keras functions into omlt_surrogate_base.py to enable simple support for multiple omlt import types
-adds ONNXSurrogate object that can load onnx model directly in IDAES flowsheet block

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1. I agree my contributions are submitted under the license terms described in the LICENSE.txt file at the top level of this directory.
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[codecov]

Codecov Report

Attention: 18 lines in your changes are missing coverage. Please review.

Comparison is base (d45e2ad) 77.43% compared to head (7ba2ba6) 77.43%.

Files	Patch %	Lines
idaes/core/surrogate/onnx_surrogate.py	78.26%	7 Missing and 8 partials ⚠️
idaes/core/surrogate/omlt_base_surrogate_class.py	94.64%	1 Missing and 2 partials ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1308   +/-   ##
=======================================
  Coverage   77.43%   77.43%           
=======================================
  Files         390      392    +2     
  Lines       63758    63844   +86     
  Branches    11737    11749   +12     
=======================================
+ Hits        49373    49440   +67     
- Misses      11841    11852   +11     
- Partials     2544     2552    +8     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[ksbeattie]

@avdudchenko @rundxdi should this be part of the next (now May) release?

[ksbeattie]

@avdudchenko @rundxdi now would be a good time to get this on the Aug release, if you can find a reviewer for it

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 85.71429% with 18 lines in your changes missing coverage. Please review.

Project coverage is 76.98%. Comparing base (0e05ed1) to head (1084f5c).

Files with missing lines	Patch %	Lines
idaes/core/surrogate/onnx_surrogate.py	77.94%	7 Missing and 8 partials ⚠️
idaes/core/surrogate/omlt_base_surrogate_class.py	94.44%	1 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1308      +/-   ##
==========================================
- Coverage   76.98%   76.98%   -0.01%     
==========================================
  Files         382      384       +2     
  Lines       61913    61995      +82     
  Branches    10130    10136       +6     
==========================================
+ Hits        47665    47728      +63     
- Misses      11848    11859      +11     
- Partials     2400     2408       +8     

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📢 Have feedback on the report? Share it here.

[ksbeattie]

@avdudchenko, this is now on the Nov 2024 release board. Can progress be picked up on this now?

[ksbeattie]

@OOAmusat, @bpaul4, @rundxdi can you review or finish your review?

[rundxdi]

Finalizing my review -- looks good at this point

[bpaul4]

I think the changes implemented here are good. Not critical to fix, there are a few places in the ONNX file that refer to "keras" instead of "onnx".

[dangunter]

@avdudchenko Can you look at the test failures and see if they can be fixed?
Also could you address Brandon's comments