Add Drupal 'trans' tag to Twig linter.

[wu-edward]

Fixes #2828.

Quick fix so that BLT Twig validation doesn't fail on the Drupal trans tag. Could possibly be more elegantly done.

This probably also needs tests.

Making this extensible to include custom/contrib module parsers/custom tags is to do as well.

Changes proposed:

• Include Drupal TwigTransTokenParser into BLT Twig environment used for linting.

[mikemadison13]

@wu-edward can you give me some steps on how to validate and test this please?

[wu-edward]

@mikemadison13

1. Add or edit a twig template in a custom Drupal theme in your BLT project.
2. In the template, use the trans tag:

{% trans %}
  Text
{% endtrans %}

Also the plural version:

{% trans %}
  Hello {{ count }} world!
{% plural count %}
  Hello {{ count }} worlds!
{% endtrans %}

3. Run blt tests:twig:lint:all
4. With this commit, there should be no errors (and there should be errors without)
5. You can also test that validation will fail if the trans tag is missing the end tag, or the plural tag is missing the parameter.

[ba66e77]

I've confirmed the changes on my local. Updating branch with latest progress on 9.x then will merge.