Improving Defaults Hyper Parameter for Binary Quantization Indexes

[Vikasht34]

Description

This PR contains changes to change default hyper parameter in case of Binary Quantization from 100 to 256 for ef Search and ef Construction and also changes the default oversampling factor from 2.x to 3.x.

Related Issues

https://github.com/opensearch-project/k-NN/issues/1949

Check List

• [x] New functionality includes testing.
• [ ] New functionality has been documented.
• [ ] API changes companion pull request created.
• [x] Commits are signed per the DCO using --signoff.
• [ ] Public documentation issue/PR created.

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