Plugin list won't scroll (WooCommerce)

Posting here as per [these comments](https://github.com/Automattic/woocommerce.com/issues/4597#issuecomment-539195670).

## Problem
The list of plugins in the support submission section of WooCommerce cannot be scrolled through. Instead results are just cut off.

Image Link: https://cld.wthms.co/iRmCI2

## Steps to reproduce
1. Go to https://woocommerce.com/my-account/create-a-ticket/
2. Click the **I need help with** drop-down menu
3. Try to scroll to select a plugin

## Expected results
Either the list should be scrollable, or we should not display the list by default and only return search results after something is typed in.

Start by reproducing the issue at the WooCommerce support submission URL and inspect the client-side implementation of the “I need help with” plugin dropdown. Done means the full plugin list can be scrolled, or the list stays hidden until a search term is entered and results are usable.

Written by the indexing model from the issue text.