Video Player: Remove grid__wrapper

[anselmbradford]

The grid__wrapper mixin has these rules:

  max-width: (@grid_wrapper-width - @grid_gutter-width);
  padding-right: (@grid_gutter-width / 2);
  padding-left: (@grid_gutter-width / 2);
  margin: 0 auto;
  clear: both;

Where @grid_wrapper-width is 1230px and @grid_gutter-width is 30px;
https://github.com/cfpb/design-system/blob/6b566bdb7ae2ce4c80a1cd05404bf3ea2e8fe6fa/packages/cfpb-grid/src/cfpb-grid.less#L20

It appears the only aspect of these rules that the video player actually uses is the left and right padding, which is the same as the top and bottom padding. This PR replaces the grid__wrapper() with padding.

Changes

• Video Player: replace the grid__wrapper() mixin with padding.

How to test this PR

1. Check that when playing, across screen sizes, that our various video layouts are unchanged, such as:

http://localhost:8000/about-us/blog/hidden-cost-junk-fees-zh/
http://localhost:8000/about-us/blog/the-cfpb-is-here-to-help-consumers-facing-housing-insecurity/
http://localhost:8000/consumer-tools/educator-tools/your-money-your-goals/videos/paying-bills-and-saving/
http://localhost:8000/language/zh/
http://localhost:8000/rules-policy/tenant-background-checks/

Some videos open the video in a new window, but still have the controls in the markup (though they aren't shown)"
http://localhost:8000/about-us/events/archive-past-events/special-populations-presentation/
http://localhost:8000/know-before-you-owe/