fix(theme-language-server-common): preserve element type on array-returning filters

[Jp-fix]

What are you adding in this PR?

Fixes #1086.

When a typed value is piped through an array-returning filter like sort, the language server was showing untyped[] on hover instead of preserving the element type. Example from the issue:

{% for media in product.media %}
  {% assign media_as_array = media | sort %}
  {# hover on `media_as_array` used to show `untyped[]` — now shows `media[]` #}
{% endfor %}

The filter docs declare array_value: "untyped" for these filters, so docsetEntryReturnType was always handing back untyped[]. Instead of changing the docs (they're pulled from Shopify/theme-liquid-docs), I added a small pass-through list in TypeSystem.ts covering sort, sort_natural, reverse, uniq, compact and where, and switched the filter chain from "only inspect the last filter" to a left-to-right reduce so chains like x | sort | reverse thread the element type correctly.

Scalar inputs (media | sort in the issue) are wrapped into an array of the same type, matching Liquid's runtime coercion.

What's next? Any followup issues?

• `map` is out of scope here — it would need to resolve a property lookup on the element type. Worth a separate PR.
• `concat` is also out of scope: the result type would be a union of both arrays' element types, which the type system doesn't represent today.

Before you deploy

• I included a patch bump `changeset`

[Jp-fix]

I have signed the CLA.