[Intelligent code completion] Introduce basic support to Liquid built-in types

[karreiro]

The goal of this issue is to manually create the data/shopify_liquid/built_in_liquid_objects.json file using https://shopify.dev/api/liquid/basics#types as a reference.

In the future, we may consider generating/introducing that file at 'Shopify/theme-liquid-docs', still as it's not theme specific, so may adopt a different direction.