Feat: Provider Tests

[narengogi]

Title:

• Tests for providers to make sure they are OpenAI compliant

Initial idea for this sprung from reading the very descriptive GitHub issue raised by @raulraja #116

Motivation: (optional)

• Multiple provider's transformers are not OpenAI spec compliant, they fail to transform cases like user message content array

    {
      role: 'user',
      content: [
        {
          type: 'text',
          text: 'Who is the greatest detective',
        },
      ],
    }

• Already caught 6 transformers failing from 12 I tested for the two test cases.

Related Issues: (optional)

• Support OPEN AI spec across providers and models #116

TO-DO:

• Push config file
• [For Later] Add flag to test only specific providers
• [For Later] GitHub actions

[narengogi]

For your review @VisargD @sk-portkey

[sk-portkey]

move from feature specific to provider level testing

[sk-portkey]

@narengogi can you update to main. else lgtm