EuiComboBox: Set react-input-autosize styles once CSS loads

[cjcenizal]

Per #567 (comment):

There's a TODO in combo_box.js which notes that we need to wait for the EUI CSS to be loaded before calling this.autoSizeInput.copyInputStyles() (docs). Ideally we should listen for the styles to load instead of using a static timeout. Until we fix this, users are bound to see the input text with the incorrect font-size and style.

[anishagg17]

@snide would it be fixed by using react-loadable ??

[chandlerprall]

react-loadable would not address as we currently rely on the downstream application to EUI's styles, we would need to poll the DOM in some fashion, likely checking a known-to-exist DOM node in checkbox for an EUI style. There isn't a programmatic way to hook react-loadable into this

As we move away from applying styles in this way, and toward some kind of CSS-in-JS solution, this issue goes away entirely. I've never witnessed the issue this potentially causes, and haven't heard of it from anyone else, so I am going to close this. If someone has a demonstrataable case I'm happy to re-open.