Fix analysis/plotly and ax/plot for scalarized objectives/constraints

[saitcakmak]

Summary:

• ObjectivePFeasibleFrontierPlot: Add scalarized guard in
  validate_applicable_state and compute since metric_names[0] and
  .minimize are semantically wrong for scalarized objectives.
• Fix scalarized outcome constraint guard: change
  isinstance(oc, ScalarizedOutcomeConstraint) to
  len(oc.metric_names) > 1 to catch expression-based scalarized
  constraints (not just the deprecated class).
• _maybe_get_default_minimize_single_metric: Change
  if optimization_config.is_moo_problem: to
  if not objective.is_single_objective: to cover scalarized objectives
  using the same metric_weights logic.

Reviewed By: lena-kashtelyan

Differential Revision: D97123687

[meta-codesync]

@saitcakmak has exported this pull request. If you are a Meta employee, you can view the originating Diff in D97123687.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 87.50000% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 96.30%. Comparing base (04c9aba) to head (c91be71).

Files with missing lines	Patch %	Lines
...x/analysis/plotly/objective_p_feasible_frontier.py	85.71%	1 Missing ⚠️
ax/plot/pareto_frontier.py	75.00%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #5068   +/-   ##
=======================================
  Coverage   96.29%   96.30%           
=======================================
  Files         613      613           
  Lines       67232    67238    +6     
=======================================
+ Hits        64742    64752   +10     
+ Misses       2490     2486    -4     

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[meta-codesync]

This pull request has been merged in 9d15a15.