Vsb single namespace

[vkrishna1084]

Problem

VSB previously lacked support for working with namespaces. Data could only be loaded into or queried from the default namespace at the index level.

Solution

This update extends VSB to support namespaces by adding functionality to:

1. Check if the namespace exist.
2. Overwrite a namespace if it already exists (when specified).
3. Load data into a specified namespace within an index.
4. Query data from a specified namespace within an index.
5. Fetch data from a specified namespace within an index.
6. Delete records from a specified namespace within an index.

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update
• Infrastructure change (CI configs, etc)
• Non-code change (docs, etc)
• None of the above: (explain here)

Test Plan

1. Run the benchmarking with a specified namespace (see Pinecone ReadMe for instructions).
2. Test with an existing namespace (without --overwrite) → the process should fail.
3. Test with an existing namespace and --overwrite → the existing namespace should be deleted and recreated, with new data loaded.
4. Test with an existing namespace and --skip_populate → the populate phase should be skipped, and the query phase should run directly.