KIP-147 — Add missing type parameters to StateStoreSupplier factories and KGroupedStream/Table methods

Discarded Streams

KIP-147 adds proper generic type parameters to `StateStoreSupplier` and the `KGroupedStream`/`KGroupedTable` aggregation methods that accept store suppliers, enabling the compiler to catch type mismatches (e.g. passing a `WindowStore` supplier to a `KeyValueStore`-expecting method) at compile time. The raw-typed `StateStoreSupplier` argument in aggregation APIs prevents IDE and compiler tooling from detecting incorrect store type pairings during refactoring.

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