Fix EfCoreEnvelopeTransaction batch outgoing envelopes using wrong storage command

[jeremydmiller]

Summary

• Fixes a bug in EfCoreEnvelopeTransaction.PersistOutgoingAsync(Envelope[]) where the non-Wolverine-enabled DbContext path was calling DatabasePersistence.BuildIncomingStorageCommand instead of BuildOutgoingStorageCommand
• This caused batch outgoing envelopes to be inserted with incoming table schema/fields rather than the outgoing table
• The single-envelope PersistOutgoingAsync(Envelope) overload was already correct; only the array overload was affected
• Adds a regression test that verifies batch outgoing envelopes are written to the outgoing table (not incoming) when using a non-Wolverine-mapped DbContext

Closes #2474

Test plan

• New integration test persist_batch_outgoing_envelopes_uses_outgoing_table in eager_idempotency_with_non_wolverine_mapped_db_context verifies envelopes appear in AllOutgoingAsync() and not AllIncomingAsync() after the fix
• Requires SQL Server docker container running (docker compose up -d)

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