Update language models and tests for Azure OpenAI

[jdubois]

This PR update the language models for Azure OpenAI, and improves some tests:

• It updates the current models available on Azure OpenAI, removing those which are not available like gpt-4-0314, gpt-3.5-turbo-0301
• It creates some upcoming models as described in https://openai.com/blog/new-embedding-models-and-api-updates
• It passes those updated model names to the integration tests and fixes some issues there: I have no idea why we were testing for "length" and not for "stop", so now we do both correctly.
• Also the Dall E 3 test was "disabled", so I enabled it again.

[langchain4j]

@jdubois awesome, thank you!

[langchain4j]

You might want to split this class into multiple enums: one per model type, like OpenAiChatModelName, OpenAiEmbeddingModelName, etc. These enums can be then accepted by model builder for convenience (in addition to strings).