Spanish Home and Landing pages don't have Subheading field

[sarinapadilla]

Issue description

The optional subheading field on H&L pages displays for English, but not for Spanish. Also, the Spanish page currently displays the English subheading if it is set on the front end.

We need to make this field translatable so Spanish can have different subheadings than English, or will not display a heading if the Spanish subheading isn't set while the English is.

ESTIMATE TBD

Steps to reproduce the issue

Drupal UI:

1. Edit an existing Home and Landing content item and view the Spanish translation Editing page

Cgov:

1. Create a Spanish translation of an existing Home and Landing content item
2. Set the Subheading field on the English content item
3. Publish both pages

What's the expected result?

Drupal UI:

• The "Subheading" field is displayed

Cgov:

• The Spanish page does not display the English subheading.

What's the actual result?

Drupal UI:

• The "Subheading" field is not displayed

Cgov:

• The Spanish page displays the English subheading.