feat(statics): add CoinFeature.STAKING to txdc coin features

Enable staking feature for txdc (testnet XDC) so WalletPlatform and
bitgo-ui can identify XDC testnet as staking-capable. The mainnet xdc
coin is intentionally left unchanged pending full go-live.

- Add CoinFeature.STAKING to txdc via inline spread in allCoinsAndTokens.ts
- Add txdc to coinsWithExcludedFeatures in statics unit test
- Add STAKING feature assertion to sdk-coin-xdc test

Ticket: SC-5664

Author: Doddanna17

modules/sdk-coin-xdc/test/unit/xdc.ts

@@ -4,6 +4,7 @@ import { TestBitGo, TestBitGoAPI } from '@bitgo/sdk-test';
 import { BitGoAPI } from '@bitgo/sdk-api';
 
 import { Xdc, Txdc } from '../../src/index';
+import { CoinFeature } from '@bitgo/statics';
 import { UnsignedSweepTxMPCv2 } from '@bitgo/abstract-eth';
 import { mockDataUnsignedSweep, mockDataNonBitGoRecovery } from '../resources';
 import nock from 'nock';
@@ -43,6 +44,7 @@ describe('xdc', function () {
       txdc.getBaseFactor().should.equal(1e18);
       txdc.supportsTss().should.equal(true);
       txdc.allowsAccountConsolidations().should.equal(false);
+      txdc.features.includes(CoinFeature.STAKING).should.equal(true);
     });
   });
 });

modules/statics/src/allCoinsAndTokens.ts

@@ -1538,7 +1538,7 @@ export const allCoinsAndTokens = [
     18,
     UnderlyingAsset.XDC,
     BaseUnit.ETH,
-    XDC_FEATURES
+    [...XDC_FEATURES, CoinFeature.STAKING]
   ),
   account(
     '297edf01-b166-45fb-be6f-da6680635f72',

modules/statics/test/unit/coins.ts

@@ -725,6 +725,9 @@ const coinsWithExcludedFeatures: Record<string, { features: CoinFeature[] }> = {
       CoinFeature.CUSTODY_BITGO_FRANKFURT,
     ],
   },
+  txdc: {
+    features: [CoinFeature.STAKING],
+  },
 };
 
 describe('CoinMap', function () {