Fix accessing state for reactor networks containing FlowReactor

[speth]

Changes proposed in this pull request

• Add missing +translate_exception annotation for ReactorNet.getState
• Add get_state_dae member for Python ReactorNet and FlowReactor classes

The first commit here should be cherry-picked into #2092.

AI Statement (required)

• Limited use of generative AI. Standard or boilerplate code snippets were generated with AI and manually reviewed; all design, logic, and implementation decisions were made by the contributor. Examples: IDE code-completions or brief LLM queries for common patterns.

Checklist

• The pull request includes a clear description of this code change
• Commit messages have short titles and reference relevant issues
• Build passes (scons build & scons test) and unit tests address code coverage
• Style & formatting of contributed code follows contributing guidelines
• AI Statement is included
• The pull request is ready for review

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 77.55%. Comparing base (5864c86) to head (264383e).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2098   +/-   ##
=======================================
  Coverage   77.55%   77.55%           
=======================================
  Files         451      451           
  Lines       52834    52846   +12     
  Branches     8836     8836           
=======================================
+ Hits        40973    40984   +11     
- Misses       8887     8888    +1     
  Partials     2974     2974           

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[ischoegl]

Thanks, @speth!