add JinaEncoder class to handle Jina Embeddings

[JoanFM]

Adding JinaEncoder class to allow users to use Jina Embeddings using Jina Embedding API https://jina.ai/embeddings/

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

Unit tests have been added

[JoanFM]

Adding unit tests to class

[JoanFM]

Adding unit tests to class

Done

[igiloh-pinecone]

@JoanFM thank you very much for your contribution!

Please see only one comment about missing a system (==integration) test. Other than that LGTM

[igiloh-pinecone]

For encoders that use external APIs, on top of the highly mocked unit test we also have a system test that verifies integration with the actual embedding service. Please see tests/system/test_openai_encoder for example.

Can you please add a similar system test for JinaEncoder?
These tests can assume that JINA_API_KEY env var has a valid API key, and we will add a relevant key to the CI's secrets.

[JoanFM]

Hey @igiloh-pinecone ,

System test added as request. Please check

[igiloh-pinecone]

LGTM!