feat: add translation metadata and quick ai translations

[jeremydw]

This PR adds two major features:

1. Metadata on translatable fields
2. Quick AI translations

The current metadata options are:

1. Description - Included in translation requests (in ARB files and AI translations)
2. "Do Not Translate" checkbox. If this is checked, the string isn't extracted or sent for translation.

The metadata is stored as:

{
  fieldName: 'Value',
  @fieldName: {
    translations: {
      doNotTranslate: true,
      description: 'Foo bar'
    }
  }
}

When "do not translate" is checked the icon in the doc editor switches to red with a strike through it.

[stevenle]

I think I would prefer a flatter structure for metadata, and the enableFoo/disableFoo nomenclature. E.g.:

{
  fieldName: 'Value',
  @fieldName: {
    disableTranslations: true,
    description: 'Lorem ipsum'
  }
}

[stevenle]

Couple of other notes:

• the purple ai icon would be a new color for the cms, i don't think purple is used anywhere else. i think i'd prefer our action icons to be consistent, although this is a useful feature i don't think it needs the prominence of a strong color here
• the red strikeout in the icon also feels a little too prominent for me, i think having it strikedout with the normal black color is good enough (with a tooltip that says "translations are disabled").

[stevenle]

(also noting that one of the unit tests are failing)

[jeremydw]

Done - all should be updated now

[stevenle]

Style nit: comments should end in punctuation.

[stevenle]

This might be worth extracting to its own function and adding unit tests for it.

[stevenle]

loop-based string concatentation is expensive, use arrays for building strings

[stevenle]

What's the purpose of providing it with existing translations? Can we ignore locales we already have translations for in this request, to avoid overwriting existing translations?

[jeremydw]

Providing it with the existing translations was my idea to help it establish more context; e.g. if you have 10 locales translated and one missing; the tone can be inferred from the existing translations to make the missing one more accurate.

It won't overwrite any existing translations (it just uses them to improve the style of the translations it's getting). I've added a comment that clarifies that to EditTranslationsModal.

[jeremydw]

Done - updated