memgraph-lab: Add feature for users to specify OpenAI base URL

[theobjectivedad]

This feature would allow users who are hosting their own LLMs using OpenAI API compatible services such as vllm, aphrodite-engine, and others to use them with the memgraph-lab AI chat.

Broadly, users would just need a way to override the baseURL for the OpenAI connection type, no other changes would be needed.

[katarinasupe]

Hi @theobjectivedad, thank you for filing this feature request. We'll keep you updated 😄

[tonilastre]

This feature was released in Lab v2.16.0.