Allow prop highlightTreeNode to be passed in or match custom filterTreeNode with highlighting

If I pass in filterTreeNode, I am able to customize which items are filtered. However, that is different from what is highlighted. I'd like for the highlighting to be consistent with the filtering. The easiest way would be to check if filterTreeNode is defined, and if so, apply highlighting based on that prop, rather than highlighting independently

https://github.com/react-component/tree-select/blob/master/src/SelectTrigger.jsx#L175

For example:
filterTreeNode={(input, child) => { return child.props.value.toLowerCase().indexOf(input.toLowerCase()) > -1}}

I'd expect the highlight function to match:
highlightTreeNode={(input, child) => { return child.props.value.toLowerCase().indexOf(input.toLowerCase()) > -1}}

But since highlightTreeNode is not a valid prop, the highlighting is different

Start at src/SelectTrigger.jsx around line 175 and inspect how filterTreeNode and highlighting are applied during search. The change is done when a custom filterTreeNode produces matching highlighting, or an explicit highlightTreeNode prop is supported consistently with the requested behavior.