feat(react-query): add 'QueryStrictMode'

.changeset/query-strict-mode.md

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+---
+'@tanstack/react-query': minor
+---
+
+feat(react-query): add `QueryStrictMode`, which reports missing prefetches (a query hook starting the initial fetch of its query; `event.suspense` tells suspense hooks apart) and unused prefetches (a prefetched query nobody reads within `unusedPrefetchTimeout`) in development. Problems are passed to `handler`, which throws a `QueryStrictModeError` to an error boundary by default; pass a `handler` that returns, for example one that logs `event.message`, to report problems without throwing. In production it only renders `children`.