## Summary
Adds live ETL indexing for mptoken_issuance_history by extracting MPT
issuance references from transaction metadata and transaction fields,
then writing both MPT transaction index shapes during the existing MPT
ETL pass. Successful transactions are indexed from affected MPT ledger
objects; failed transactions are indexed only when they carry an
attached MPT issuance reference.
## Changes
- Adds `getMPTokenIssuanceTxsFromTx` to extract issuance transaction
index records from `tesSUCCESS` transactions.
- Scans `AffectedNodes` generically for `MPToken` and `MPTokenIssuance`
ledger objects instead of relying on a transaction-type allowlist.
- Reconstructs issuance IDs for `MPTokenIssuance` objects with
`makeMptID(sequence, issuer)`, avoiding the hashed ledger-key trap.
- Deduplicates distinct issuances per transaction and attaches the
transaction’s affected accounts for account-level fanout.
- Extends `MPTExt` so live and initial ETL data writes:
- existing MPT holder index data
- `mptoken_issuance_transactions`
- `account_mptoken_issuance_transactions`
- Adds a Prometheus counter for MPT issuance transaction index rows
written by ETL.
- Logs unexpectedly large per-transaction fanout.
## Tests
Adds unit coverage for:
- failed transactions producing no records
- `MPTokenIssuanceCreate`, `Destroy`, `Set`, and `MPTokenAuthorize`
- generic transaction-type coverage through `Payment`, `Clawback`,
`OfferCreate`, and `AMMDeposit`
- ID reconstruction from issuance nodes
- multi-issuance fanout and deduplication
- affected-account propagation
- ETL extension writes to both backend index paths while preserving
existing holder indexing
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Co-authored-by: Ayaz Salikhov <mathbunnyru@users.noreply.github.com>
