Input: Throw error if action doesn't exist

Thow errors if requesting an unexisting InputMap action.
Makes `Input.is_action_*` methods consistents with `Event.is_action_*` which already throw errors.

fixes #33303

core/input/input.cpp

@@ -241,10 +241,18 @@ bool Input::is_joy_button_pressed(int p_device, int p_button) const {
 }
 
 bool Input::is_action_pressed(const StringName &p_action, bool p_exact) const {
+#ifdef DEBUG_ENABLED
+	bool has_action = InputMap::get_singleton()->has_action(p_action);
+	ERR_FAIL_COND_V_MSG(!has_action, false, "Request for nonexistent InputMap action '" + String(p_action) + "'.");
+#endif
 	return action_state.has(p_action) && action_state[p_action].pressed && (p_exact ? action_state[p_action].exact : true);
 }
 
 bool Input::is_action_just_pressed(const StringName &p_action, bool p_exact) const {
+#ifdef DEBUG_ENABLED
+	bool has_action = InputMap::get_singleton()->has_action(p_action);
+	ERR_FAIL_COND_V_MSG(!has_action, false, "Request for nonexistent InputMap action '" + String(p_action) + "'.");
+#endif
 	const Map<StringName, Action>::Element *E = action_state.find(p_action);
 	if (!E) {
 		return false;
@@ -262,6 +270,10 @@ bool Input::is_action_just_pressed(const StringName &p_action, bool p_exact) con
 }
 
 bool Input::is_action_just_released(const StringName &p_action, bool p_exact) const {
+#ifdef DEBUG_ENABLED
+	bool has_action = InputMap::get_singleton()->has_action(p_action);
+	ERR_FAIL_COND_V_MSG(!has_action, false, "Request for nonexistent InputMap action '" + String(p_action) + "'.");
+#endif
 	const Map<StringName, Action>::Element *E = action_state.find(p_action);
 	if (!E) {
 		return false;
@@ -279,6 +291,10 @@ bool Input::is_action_just_released(const StringName &p_action, bool p_exact) co
 }
 
 float Input::get_action_strength(const StringName &p_action, bool p_exact) const {
+#ifdef DEBUG_ENABLED
+	bool has_action = InputMap::get_singleton()->has_action(p_action);
+	ERR_FAIL_COND_V_MSG(!has_action, false, "Request for nonexistent InputMap action '" + String(p_action) + "'.");
+#endif
 	const Map<StringName, Action>::Element *E = action_state.find(p_action);
 	if (!E) {
 		return 0.0f;