Allow specifying display names for trials and experiments

**Is your feature request related to a problem? Please describe.**
The create methods for [Trial](https://sagemaker-experiments.readthedocs.io/en/latest/trial.html#smexperiments.trial.Trial.create) and [Experiment](https://sagemaker-experiments.readthedocs.io/en/latest/experiment.html#smexperiments.experiment.Experiment.create) are both lacking the option to specify a display name, which is a request property on the [CreateExperiment](https://docs.aws.amazon.com/sagemaker/latest/APIReference/API_CreateExperiment.html) and [CreateTrial](https://docs.aws.amazon.com/sagemaker/latest/APIReference/API_CreateTrial.html) APIs.

**Describe the solution you'd like**
Add the `display_name` as an optional argument to the create methods.