Improve wording for UNKNOWN states

The original wording comes from the API specs docs (for example
https://github.com/frequenz-floss/frequenz-api-microgrid/blob/2332734e86dd8c1d3bf4ee601b93d52525654a6f/proto/frequenz/api/microgrid/inverter.proto#L70-L72),
but we change the wording here to make it more clear.

Co-authored-by: Sahas Subramanian <[email protected]>
Signed-off-by: Leandro Lucarella <[email protected]>

Author: llucax

src/frequenz/client/microgrid/_component_states.py

@@ -49,7 +49,7 @@ class BatteryComponentState(Enum):
     """The battery is switching off and needs some time to fully shut down."""
 
     UNKNOWN = battery.ComponentState.COMPONENT_STATE_UNKNOWN
-    """The state is provided by the device, but it is not one of the above states."""
+    """A state is provided by the component, but it is not one of the above states."""
 
     @classmethod
     def from_pb(cls, state: battery.ComponentState) -> Self:
@@ -176,7 +176,7 @@ class EVChargerComponentState(Enum):
     """The component is interrupted."""
 
     UNKNOWN = ev_charger.ComponentState.COMPONENT_STATE_UNKNOWN
-    """The state is provided by the device, but it is not one of the above states."""
+    """A state is provided by the component, but it is not one of the above states."""
 
     @classmethod
     def from_pb(cls, state: ev_charger.ComponentState) -> Self:
@@ -237,7 +237,7 @@ class InverterComponentState(Enum):
     """
 
     UNKNOWN = inverter.ComponentState.COMPONENT_STATE_UNKNOWN
-    """The state is provided by the device, but it is not one of the above states."""
+    """A state is provided by the component, but it is not one of the above states."""
 
     @classmethod
     def from_pb(cls, state: inverter.ComponentState) -> Self: