Improve validate_applicable_state error messages - High Priority Updates (#5126)

[shrutipatel31]

Summary:

Fix actively misleading or broken NotApplicableState error messages across ax/analysis:

• utils.py: Replace raw Python kwarg f-string syntax ({trial_indices=}, {trial_statuses=}) with readable key=value output in validate_experiment_has_trials messages
• utils.py: Remove raw Adapter repr ({adapter}) from validate_adapter_can_predict messages; replace with user-readable text
• best_trials.py: Replace backtick-quoted class names (OptimizationConfig, GenerationStrategy) with plain-language descriptions and actionable steps
• sensitivity.py: Replace opaque "TorchAdapter is required." with a message explaining what the user needs to do
• top_surfaces.py: Remove {type(relevant_adapter)} type repr; replace with plain-language message matching sensitivity.py
• marginal_effects.py: Fix typo "but got.'" (missing space before quote) and remove {type(parameter).__name__} internal class name from error message
• objective_p_feasible_frontier.py: Fix "Optimization_config" underscore bug (should read "optimization config"), and replace raw Adapter repr ({relevant_adapter}, {relevant_adapter.generator}) with __name__ type strings

Differential Revision: D97528392

[meta-codesync]

@shrutipatel31 has exported this pull request. If you are a Meta employee, you can view the originating Diff in D97528392.