### Godot version

4.2 RC2

### System information

Any

### Issue description

AnimationMixer separates the accuracy of how discrete keys are retrieved when seeking between internal seeking and external seeking. FYI: https://github.com/godotengine/godot/pull/80708.

Since AnimationPlayer currently treats everything as an internal seek, so it needs to propagate the external seek information.

### Steps to reproduce

Seek AnimationTrackEditor

### Minimal reproduction project

[gd_anim_unittest_1.zip](https://github.com/godotengine/godot/files/13492063/gd_anim_unittest_1.zip)

r_ret = get_callback_mode_method();
	} else if (name == "playback_process_mode") {
		r_ret = get_callback_mode_process();
	} else if (name == "playback_active") {
		r_ret = is_active();
#endif 
	} else {
		return false;
	}
	return true;
}
void AnimationPlayer::_validate_property(PropertyInfo &p_property) const {
	AnimationMixer::_validate_property(p_property);
	if (p_property.name == "current_animation") {
		List<String> names;
		for (const KeyValue<StringName, AnimationData> &E : animation_set) {
			names.push_back(E.key);
		}
		names.push_front("[stop]");
		String hint;
		for (List<String>::Element *E = names.front(); E; E = E->next()) {
			if (E != names.front()) {
				hint += ",";
			}
			hint += E->get();
		}
		p_property.hint_string = hint;
	}
}
void AnimationPlayer::_get_property_list(List<PropertyInfo> *p_list) const {