Allow Site owner to "hide" or not load the "Group Account Information" on checkout page

[kimwhite]

Is your feature request related to a problem? Please describe.
A site may be configured to give a Group Code by default to a level but does not need to show or explain this on the checkout page.

Describe the solution you'd like
A filter to not load this section on the checkout page

Describe alternatives you've considered
Add an ID in the div so users can easily hide this section.

pmpro-group-accounts/includes/parents.php

Line 29 in 0aa8bef

<div class="pmpro_checkout">

[dwanjuki]

Another customer wanted to hide this section.
Mods: #550414

Gave them a CSS workaround: https://gist.github.com/dwanjuki/8082ded2d9c36363186069e83b5e59d4