Clarify that event handling does not affect `Input`

(cherry picked from commit 732ad382a64e983c002a640f0220135835bab354)

doc/classes/Control.xml

@@ -209,6 +209,7 @@
 			<return type="void" />
 			<description>
 				Marks an input event as handled. Once you accept an input event, it stops propagating, even to nodes listening to [method Node._unhandled_input] or [method Node._unhandled_key_input].
+				[b]Note:[/b] This does not affect the methods in [Input], only the way events are propagated.
 			</description>
 		</method>
 		<method name="add_theme_color_override">

doc/classes/Input.xml

@@ -5,6 +5,7 @@
 	</brief_description>
 	<description>
 		A singleton that deals with inputs. This includes key presses, mouse buttons and movement, joypads, and input actions. Actions and their events can be set in the [b]Input Map[/b] tab in the [b]Project &gt; Project Settings[/b], or with the [InputMap] class.
+		[b]Note:[/b] The methods here reflect the global input state and are not affected by [method Control.accept_event] or [method Viewport.set_input_as_handled], which only deal with the way input is propagated in the [SceneTree].
 	</description>
 	<tutorials>
 		<link title="Inputs documentation index">$DOCS_URL/tutorials/inputs/index.html</link>

doc/classes/Viewport.xml

@@ -197,6 +197,7 @@
 			<return type="void" />
 			<description>
 				Stops the input from propagating further down the [SceneTree].
+				[b]Note:[/b] This does not affect the methods in [Input], only the way events are propagated.
 			</description>
 		</method>
 		<method name="set_positional_shadow_atlas_quadrant_subdiv">