[HRnet] Dropdown menus are slow and inconsistent

[mja2128]

The dropdowns that we are currently using in the Create Employee form, for selection of address state and employee department, are pretty slow and behave inconsistently sometimes. Users have reported the order of the dropdown options changing unexpectedly, as well as other issues such as seeing very long load times to populate the options. Let's create a React component for this and see if we can speed it up and stabilize it.

This is the jQuery plugin that we are currently using for our dropdowns: https://github.com/jquery/jquery-ui/blob/master/ui/widgets/selectmenu.js

Here's an example of what it looks like in our app: