MON-4025 add caas split get transactions

[ingridacero]

Description

Adds the caas:transaction_splits:read scope to the caasGetTransactions request so transaction splits are returned by GET /transactions.

The mh-api-gateway only includes the splits array when the access token carries caas:transaction_splits:read. Previously the SDK requested only caas:transactions:read, so splits were always stripped from the response. The request now asks for both scopes. The client-credentials grant filters requested scopes against the client's allow-list and silently drops any it is not registered for, so clients with the splits scope receive splits and clients without it are unaffected (no grant failure, just no splits). No separate method is introduced and the public API surface is unchanged.

Screenshots, Recordings

This PR includes:

• Unit tests
• Contract tests
• Logging
• Monitoring
• Dependencies updates
• Swagger/Documentation changes

Added config changes?

• Yes, add more details and remember to add them in ETCD
• No

Added database migrations/resources (db, collection, table, column)?

• No

Are there any post deployment tasks that need to be performed?

Clients that need splits returned must be registered for the caas:transaction_splits:read scope in identity. No change is required for clients that do not use splits.

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Note

Low Risk
Narrow OAuth scope change on an existing CAAS read call with no API signature change; unregistered clients should be unaffected by scope filtering at token grant.

Overview
caasGetTransactions now requests caas:transactions:read and caas:transaction_splits:read on the client-credentials grant (previously only transactions read). The gateway only returns a splits array when the token includes the splits scope, so this fixes split data being omitted for clients that are allowed that scope.

The public method signature is unchanged. Clients not registered for caas:transaction_splits:read should still get tokens without that scope (filtered at grant time) and behave as before. The readme caasGetTransactions section documents both scopes and when splits appear.

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