Added Dimensionality Setting to Embedding Client

[sgeorgevv]

Add support for output dimension control in embedding models

This PR adds the ability to specify a reduced output dimension for embedding models. Key changes:

• Add optional outputDimension field to EmbeddingModel
• Add SetOutputDimension method for configuration
• Update request handling to include dimension when specified
• Propagate dimension parameter through batch operations

Supports the functionality described in the API docs: "Optional reduced dimension for the output embedding. If set, excessive values in the output embedding are truncated from the end. Supported by newer models since 2024."

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