Refactor OpenAIEmbeddings

[mehmetbutgul]

Refactor OpenAIEmbeddings annotator

Description

Refactor OpenAIEmbeddings 1- Supported escape chars that break the Open AI json content. 2- Changed the output annotator type. DOCUMENT --> SENTENCE_EMBEDDINGS NOTE: This approach is the reverse of the backward compatibility 3- Added metadata which comes from the document column to output embeddings 4- Added Python unit test class 5- Added a new submodule to support saving/loading the annotator NOTE: The new submodule will fix saving/loading the annotator

Motivation and Context

How Has This Been Tested?

Tested via Python and Scala locally. Additionally, I added new unit tests that cover my changes.

Screenshots (if appropriate):

Types of changes

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] Code improvements with no or little impact
• [ ] New feature (non-breaking change which adds functionality)
• [x] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [x] My code follows the code style of this project.
• [ ] My change requires a change to the documentation.
• [x] I have updated the documentation accordingly.
• [x] I have read the CONTRIBUTING page.
• [x] I have added tests to cover my changes.
• [x] All new and existing tests passed.

[mehmetbutgul]

I created my branch from the master, So, There are some other commits, too.