Add and apply Naming/PredicateMethod RuboCop 1.76 rule

This rule was introduced in RuboCop 1.76.0 to ensure methods ending
in '?' return boolean.

This commit applies suggested renames and code cleanup:
- Renames 'is_active?' to 'active_class' since it returns a string
- Renames 'parsed_value' to 'in_favor?' and 'is_request_active' to end with '?'
  for boolean semantics
- Skips false positives like 'save', 'auto_labels' or 'save_requiring_finish_signup',
  which are not predicate methods.

.rubocop.yml

@@ -354,6 +354,14 @@ Naming/BlockForwarding:
     - "app/controllers/management/base_controller.rb"
     - "app/controllers/subscriptions_controller.rb"
 
+Naming/PredicateMethod:
+  Enabled: true
+  Exclude:
+    - "app/models/local_census_records/import.rb"
+    - "app/models/user.rb"
+    - "app/models/verification/management/email.rb"
+    - "config/initializers/foundation_form_builder.rb"
+
 Naming/RescuedExceptionsVariableName:
   Enabled: true