Multiple endpoint support

[abose]

Currently, the coco client can only support one endpoint, we should have an API that can generate new clients without breaking backward compatibility.

For Eg. there will be the global init and other apis that esisst as is now, then we can have another API client=createClient(endpoint, apiKey) and then call client.close(), client.createDatabase() or other apis. This will ensure backward compatibility as well as new apis.