fix: fix missing native transfers in all-transactions for multiSend o…

[crlosif]

ref #2764
…n chains without tracing

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What was wrong? 👾

Closes #

How was it fixed? 🎯

• Decode multiSend batch data when a multisig tx has no indexed native transfers and add synthetic ETHER_TRANSFER entries from valueDecoded (operation=CALL, value>0).
• Enrich transfer_dict only when ether_count is 0 to avoid duplicating transfers on chains that do provide tracing (e.g. Sepolia).
• Add _get_native_transfers_from_multisend and _enrich_transfers_from_multisend_decoded in TransactionService.
• Add test_multisend_native_transfers_enriched_when_no_traces.

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[crlosif]

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