Add a better t filter to pattern lab so it plays well with Drupal

[ccjjmartin]

Purpose:

• Add a better t filter to pattern lab so it plays well with Drupal

Description:

• While looking at the pager example I noticed that someone had copied and pasted a Drupal template.
• I then realized that the t function we were using in Pattern lab didn't support string replacements.
• Now it does.

NOTE:

• We should discuss if we are merging straight to master or using the develop branch. I recently updated the develop branch because it was very out of date against master
• Looks like other functions we might want to implement are found here: https://api.drupal.org/api/drupal/core%21lib%21Drupal%21Core%21Template%21TwigExtension.php/class/TwigExtension/8.2.x
• Another Drupal.Org page: https://www.drupal.org/docs/8/theming/twig/functions-in-twig-templates

Testing:

• Go to the pager molecule and hover over the page numbers. This fix should now display "Go to page 3" instead of "Go to page @key"

[evanmwillhite]

@ccjjmartin looks awesome. Thanks!

[ccjjmartin]

@evanmwillhite Let's discuss adding other Drupal functions in the next Frontend PG so that they don't cause weird errors like this one did.