Add Preformatted class for logging preformatted messages

[jsiirola]

Fixes # .

Summary/Motivation:

MindtPy and PyROS both want to emit solver iteration logs and do NOT want those messages to be reformatted or line-wrapped. Their current solution is to hijack the entire Pyomo logging system to suppress the automatic formatting that the default log handler implements. This PR simplifies that by defining a Preformatted class that users can wrap a preformatted log message in before sending it to the logger. These messages will then be directly emitted (without being processed by the default formatter). As Preformatted is castable to str, it is compatible with other user-defined log handlers / formatters (without requiring any specialized handling).

Changes proposed in this PR:

• define a Preformatted wrapper class for logging preformatted messages
• Update the default Pyomo formatter to ignore / do not reformat Preformatted messages.
• Add tests

Legal Acknowledgement

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1. I agree my contributions are submitted under the BSD license.
2. I represent I am authorized to make the contributions and grant the license. If my employer has rights to intellectual property that includes these contributions, I represent that I have received permission to make contributions and grant the required license on behalf of that employer.

[codecov]

Codecov Report

Patch coverage: 100.00% and project coverage change: +0.22% 🎉

Comparison is base (c471729) 87.85% compared to head (7776828) 88.08%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2998      +/-   ##
==========================================
+ Coverage   87.85%   88.08%   +0.22%     
==========================================
  Files         769      769              
  Lines       89497    89507      +10     
==========================================
+ Hits        78632    78838     +206     
+ Misses      10865    10669     -196     

Flag	Coverage Δ
linux	85.18% <100.00%> (+1.44%)	⬆️
osx	74.98% <100.00%> (+<0.01%)	⬆️
other	85.36% <100.00%> (+1.45%)	⬆️
win	82.42% <100.00%> (+0.04%)	⬆️

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Files Changed	Coverage Δ
pyomo/common/log.py	97.12% <100.00%> (+0.17%)	⬆️

... and 7 files with indirect coverage changes

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[mrmundt]

Lovely and elegant solution. Minor grammar weirdness.

[shermanjasonaf]

Looks good to me.