Feature/add dimension in embedding

[prabhupant]

Thanks for submitting a pull request! Please check CONTRIBUTING.md for style guidelines.

Changes

Addresses #469 This change-set adds dimension field in EmbeddingRequest. This can be used with models that are gte second generation

New API Checklist

See CONTRIBUTING.md for more info.

1. [x] Documentation for every variable
2. [x] Class-level documentation
3. [x] POJO JSON parsing tests
4. [ ] Service integration tests