Add Language to VA Forms audit view filters

[jilladams]

Description

We'd like to be able to filter forms by populated Language attribute, or NULL.

https://prod.cms.va.gov/admin/content/va-forms/audit

User story

AS A product owner
I WANT to be able to easily check which forms are in English, Spanish, or don't have a language specified
SO THAT I can work with Forms managers to populate language on forms where it's not yet.

Additional context

Form language is a required field.
However: many forms are imported from the Forms DB without a language specified, and that is allowed / we do not fail the Forms migration on missing languages. If/when a Form is later edited within the Drupal UI, Editors must specify a language in order to save the Form form.

Acceptance criteria

• VA Forms audit view includes a Form Language filter
  • Filter includes all Form Language field options, and "Null" or "Is empty" to show which Forms have no language specified

[jilladams]

Links to use for Prod verification once Christian's changes deploy :

• English
• Spanish
• Tagalog
• No lang declared

All show all moderation statuses. To get a valid count of forms by language, we'll need to count Published + Draft.

[jilladams]

Verified in prod:

689 total forms in Draft + Published

Lang	Published	Draft	Total
English	165	279	444 total
Spanish	0? blank view	2	2
Tagalog	0?	0	0
No language declared	241 total 126 VBA 112 VHA can't tell about VACO yet	2 both VHA	243 total

Somethings a little weird in the Audit view, as VACO no longer appears as a Form administration. Wondering if that is related to #12933 or something else. TBD. Will file a sep ticket for that.