fix(ui): preserve column visibility during pagination

[ertugakmann]

What?

Fixes an issue where collection table column visibility settings are lost after refreshing the browser and then navigating to another pagination page.

Why?

After a browser refresh, the columns query parameter can be represented as a JSON string in the client query state. When pagination changes, this value was JSON-stringified again, resulting in a double-encoded query parameter.

This caused the server to fail to resolve the column preference and fall back to the default columns.

How?

Avoid JSON-stringifying columns when it is already a string.

Added a regression test covering:

• changing column visibility
• refreshing the browser
• navigating to the next page
• verifying that the column visibility is preserved

Fixes #17792

[ertugakmann]

The failing localization and trash E2E checks appear to be unrelated to this change. They fail in test/localization/e2e.spec.ts and test/trash/e2e.spec.ts, while this PR only changes the collection ListQuery serialization and adds a list-view regression test.