Add OpenAI compatible provider option to provider list

[justinrobots]

Description

Add an option in the AI provider list for "OpenAI Compatible Providers (Azure, etc.)" that allows users to connect to other providers that use OpenAI compatible APIs.

Per team discussion, we will fork the existing OpenAI provider option for this.

[sergeibbb]

@eamodio , @justinrobots

There is no an easy way to change the URL. If I select the option it goes straight to API Key. But I can drop it by editing user settings.

Should I reopen this or it's better to create a follow-up?

[eamodio]

@sergeibbb Please re-test. For both Azure and Open AI-compatible, I've added the prompt for URL if the key is missing (prefilled with the last chosen URL).

[sergeibbb]

@eamodio

Now works good