fix: set-state via call (#4567)

## Context
There was an issue in the previous PR that implemented parameter
set-state via `__call__` as the value was not sent to Fluent in the
expected format.

## Change Summary
Only the first argument value is sent to Fluent while setting parameter
state via `__call__`.

## Rationale
To send the set-state value to Fluent in the correct format 

## Impact
New unittest has been added, the example script
`exhaust_system_settings_api.py` will pass.

---------

Co-authored-by: pyansys-ci-bot <[email protected]>

Author: mkundu1

doc/changelog.d/4567.fixed.md

@@ -0,0 +1 @@
+Set-state via call

src/ansys/fluent/core/solver/flobject.py

@@ -822,7 +822,13 @@ def to_python_keys(cls, value: StateT) -> StateT:
     def __call__(self, *args, **kwargs):
         """Get or set the state of the object."""
         if kwargs:
-            self.set_state(kwargs)
+            # Send value of the first key only
+            if len(kwargs) > 1:
+                warnings.warn(
+                    f"Only the first keyword argument is used when setting state at {self.python_path}.",
+                    PyFluentUserWarning,
+                )
+            self.set_state(next(iter(kwargs.values())))
         elif args:
             self.set_state(args)
         else:
@@ -1070,6 +1076,14 @@ def __init__(self, name: str | None = None, parent=None):
             cls = self.__class__._child_classes[query]
             self._setattr(query, _create_child(cls, None, self))
 
+    def __call__(self, *args, **kwargs):
+        if kwargs:
+            self.set_state(kwargs)
+        elif args:
+            self.set_state(args)
+        else:
+            return self.get_state()
+
     @classmethod
     def to_scheme_keys(cls, value, root_cls, path: list[str]):
         """Convert value to have keys with scheme names.

tests/test_settings_api.py

@@ -841,3 +841,8 @@ def test_migration_adapter_for_strings(mixing_elbow_settings_session):
         solver.settings.setup.models.discrete_phase.general_settings.unsteady_tracking.create_particles_at()
         == "particle-time-step"
     )
+
+
+def test_set_state_via_call(mixing_elbow_settings_session):
+    solver = mixing_elbow_settings_session
+    solver.settings.results.graphics.views.camera.position(xyz=[1.70, 1.14, 0.29])