Allow custom workflow names, including for instance methods

[apoliakov]

A user prefers to have this pattern:

interface Workflow<Args, Result> {
  execute(args: Args): Promise<Result>;
}
and the worflow:

export class SomeWorkflow
  extends ConfiguredInstance
  implements Workflow<{ data: Data }, Response> {
  constructor(name: string) {
    super(name);
  } 

  @DBOS.workflow() 
  async execute({ data }: { data: Data }): Promise<Response> {
    // ...workflow code here
  }
}

Want an easy way to name the workflow something other than execute