fix(client): Simplify WorkflowClient interceptors

[mjameswh]

What changed

• In WorkflowClientOptions, interceptors should now be provided as an array of interceptor object, rather than an array of factory to those objects under a field named calls.
• Previous form is still allowed though deprecated

Before:

interceptors: {
    calls: [
        (workflowId) => {
            create(...) => { ... }
        }
    ]
}

Now:

interceptors: [
    {
            create(...) => { ... }
    }
]

Why

• The indirection was not useful and made interceptors looks complicated
• As discussed in feat: Add Schedule API #937 (comment)

Checklist

• Updated tests
• Need to update doc and code samples