More Flexible WandB Interface

[AntoineRichard]

Hey there!

This is a simple PR that brings a bit more flexibility when using a WandB logger.
It's following the same logic as SKRL's implementation.

I.e. instead of passing:

wandb_project = "Whatever"

We can now use:

 wandb_kwargs = {
        "project": "jetbot_direct",
        "entity": "spacer-rl",
        "group": "zeroG",
    } 

I'm happy to make any modification, like making it backward compatible with the current default config style.

LMK,

Antoine