build: add embedding providers and related configurations

[feliciien]

This commit introduces the embedding providers feature, including OpenAI, Cohere, HuggingFace, and VoyageAI. It includes the necessary configurations, build scripts, and CI workflows to support embedding generation and reranking functionality. The changes include:

• Added .cargo/config.toml for WASM target configuration
• Updated Cargo.toml to include new embedding providers
• Added .gitignore files for embedding providers
• Introduced .env and .env.template for API key management
• Added build and test scripts for embedding providers
• Included Dockerfile for VoyageAI provider
• Added WIT bindings and common embedding functionality
• Implemented logging, rate limiting, and error handling
• Added benchmarking and testing utilities

The changes enable embedding generation and reranking capabilities across multiple providers, with support for durability, rate limiting, and comprehensive testing. This lays the foundation for integrating embedding functionality into Golem applications. link to the video https://drive.google.com/file/d/1DTFbGmM7z2ZV6T4SuZwLgrNAChZlI-zo/view?usp=sharing
/claim #1510