More explicit error for removed Query extension

[Ariana-B]

While the STAC API Query extension was previously implemented, it suffered from the same flaws in logic as the other API extensions, which meant that while it would return correct results, they risked being oddly distributed when pagination was involved. Since it is recommended to implement the Filter extension instead of Query, and since correctly re-implementing Query was not trivial, it was dropped in favour of Filter.
As mentioned in #611, pystac_client will warn users if they try to use query, but will still return results without issue. The api itself will similarly quietly ignore query if provided.
To avoid any silent failure issues down the line, return a 400 error if the request includes a query argument.

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📚 Documentation preview 📚: https://datacube-explorer--615.org.readthedocs.build/en/615/

[robbibt]

Hey @Ariana-B, this looks great. Is there any way I can test this on the STAC endpoint before merging? If not, I'll just test it out after we merge and release a new Explorer version

[robbibt]

This looks great to me - let's merge this and I'll double check it once it's live 🙂