Fixes #23434

When a query parameter is defined with type: array and uniqueItems: true, the typescript-angular generator produces a Set<T> type. However, addToHttpParams only checks Array.isArray(value) to detect collections. Since Array.isArray(new Set()) returns false, the Set falls through to the object-handling branch and query parameters are silently lost.

This adds a value instanceof Set check alongside Array.isArray(value) in the addToHttpParams method of api.base.service.mustache. When a Set is detected, it is converted to an Array before serialization.

cc @TiFu @taxpon @sebastianhaas @kenisteward @Vrolijkx @macjohnny @topce @akehir @petejohansonxo @amakhrov @davidgamero @mkusaka @joscha @dennisameling

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Summary by cubic

Fixes lost query params when uniqueItems: true arrays generate Set<T> in the typescript-angular client by serializing Set like arrays in addToHttpParams. Fixes #23434.

• Bug Fixes
  • In api.base.service.mustache, detect Set values in addToHttpParams and serialize them via Array.from(...) for form, space-delimited, and pipe-delimited styles.
  • Extended query-param-form.yaml with a tags query param (array, uniqueItems: true) on both explode and non-explode routes to produce Set<string>.
  • Regenerated typescript-angular samples across versions and updated services to accept tags: Set<string>; tests now cover Set-only and combined cases for explode and non-explode.

^{Written for commit efab0a8. Summary will update on new commits.}