[BUG] DataSourceError swallows error type attribute which is used by plugins

[BionIT]

Describe the bug
DataSourceError object swallows body.error.type from the error object causing a few plugins to have 500 error, eg anomaly detection (see ref https://github.com/search?q=repo%3Aopensearch-project%2Fanomaly-detection-dashboards-plugin%20body.error.type&type=code), index management (see ref https://github.com/search?q=repo%3Aopensearch-project%2Findex-management-dashboards-plugin%20body.error.type&type=code)

Expected behavior
The DataSourceError was thrown as a general error when failed to make a request to data source, see ref https://github.com/opensearch-project/OpenSearch-Dashboards/blame/476cffc2f793b424d68981aaaee9aa1f9fd958be/src/plugins/data_source/server/legacy/configure_legacy_client.ts#L92, we should not swallow the error type causing 500 errors due to missing prop.

OpenSearch Version
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Dashboards Version
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Plugins

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Screenshots

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Host/Environment (please complete the following information):

• OS: [e.g. iOS]
• Browser and version [e.g. 22]

Additional context

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