[FEATURE] Supports SigV4Authenticator in the server side

### What would you like to be improved?

Iceberg REST catalog has already supported

https://github.com/apache/iceberg/blob/main/aws/src/main/java/org/apache/iceberg/aws/RESTSigV4AuthManager.java

For Gravitino Iceberg REST server should validate the token and extract the principal from the token

### How should we improve?

Gravitino Iceberg REST server should validate the token and extract the principal from the token

Start by reading Apache Iceberg's RESTSigV4AuthManager referenced in the issue, then locate the Gravitino Iceberg REST server authentication entry point. The work is done when the server validates the SigV4 token and extracts the principal from it.

Written by the indexing model from the issue text.