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

[Poitrin]

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.

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