[Intelligent code completion] Support iterated objects via `for`, inside `form`

Describe the bug In the following example, when a for loop is inside a form, ICC doesn't seem to work.

{%- form 'localization', id: 'FooterLanguageFormNoScript', class: 'localization-form' -%}
  {%- for language in localization.available_languages -%}
    <option value="{{ language.⬜️

Simplified version of https://github.com/Shopify/dawn/blob/main/sections/footer.liquid#L276

Expected Expected suggestions like iso_code. Expected suggestions like iso_code

Actual Default suggestions from VS Code

Debugging information

OS [e.g. Windows, Mac, Linux]: macOS
Version (output of theme-check --version in a terminal): 1.12.0

Shopify / theme-check

[Intelligent code completion] Support iterated objects via `for`, inside `form` #681