Add support for XLS-85 Token Escrow (#5185)

- Specification: https://github.com/XRPLF/XRPL-Standards/pull/272
- Amendment: `TokenEscrow`
- Enables escrowing of IOU and MPT tokens in addition to native XRP.
- Allows accounts to lock issued tokens (IOU/MPT) in escrow objects, with support for freeze, authorization, and transfer rates.
- Adds new ledger fields (`sfLockedAmount`, `sfIssuerNode`, etc.) to track locked balances for IOU and MPT escrows.
- Updates EscrowCreate, EscrowFinish, and EscrowCancel transaction logic to support IOU and MPT assets, including proper handling of trustlines and MPT authorization, transfer rates, and locked balances.
- Enforces invariant checks for escrowed IOU/MPT amounts.
- Extends GatewayBalances RPC to report locked (escrowed) balances.

include/xrpl/protocol/detail/features.macro

@@ -32,6 +32,7 @@
 // If you add an amendment here, then do not forget to increment `numFeatures`
 // in include/xrpl/protocol/Feature.h.
 
+XRPL_FEATURE(TokenEscrow,                Supported::yes, VoteBehavior::DefaultNo)
 XRPL_FIX    (EnforceNFTokenTrustlineV2,  Supported::yes, VoteBehavior::DefaultNo)
 XRPL_FIX    (AMMv1_3,                    Supported::yes, VoteBehavior::DefaultNo)
 XRPL_FEATURE(PermissionedDEX,            Supported::yes, VoteBehavior::DefaultNo)