Fix TS error and web type

Author: M-i-k-e-l

lib/components/HighlighterOverlayView/index.web.tsx

@@ -22,7 +22,7 @@ export type HighlighterOverlayViewProps = {
   onRequestClose?: () => void;
   highlightFrame?: HighlightFrameType;
   style?: ViewStyle;
-  highlightViewTag?: number | null;
+  highlightViewTag?: number;
   children?: JSX.Element[] | JSX.Element;
   highlightViewTagParams?: HighlightViewTagParams;
   minimumRectSize?: Pick<HighlightFrameType, 'width' | 'height'>;

src/components/featureHighlight/index.tsx

@@ -133,7 +133,7 @@ export type FeatureHighlightProps = {
 interface State {
   fadeAnim: Animated.Value;
   contentTopPosition?: number;
-  node?: number | null;
+  node?: number;
   getTarget?: () => any;
 }