Support templating for Flow Run Names

[bdalpe]

Describe the current behavior

Currently, you cannot have a Deployment create a Flow run with a custom name dynamically at execution time.

This must be done through the UI, or programmatically through the use of the CLI/SDK.

Describe the proposed behavior

As a user, I would like to be able to pass a custom flow run name as part of the Prefect Deployment object.

Example Use

prefect.yaml

deployments:
  - name: my-deployment
    flow_run_name: "my-deployment-{{ datetime.now() }}"
    ...

Additional context

Based on #20262 and a discussion with another customer using the Prefect Prometheus Exporter.

[zzstoatzz]

Currently, you cannot have a Deployment create a Flow run with a custom name dynamically at execution time.

whether or not a flow is associated with a deployment, if you set the flow_run_name kwarg of the flow decorator to a callable or template string, you can template out the flow run name based on the parameters or date like this.

specifying flow_run_name in prefect.yaml would be less expressive, as you can't write a python function in yaml, but the larger problem would seem that we'd be mixing concerns. if we did this, you could reasonably ask for any flow option to be exposed in the prefect.yaml, but these are explicitly meant as options on the flow object

there's an easy way to not need a new flow_run_name key on the deployment object and its using with_options

@flow
def parent(some_args, workflow_name: str):
   workflow.with_options(flow_run_name=workflow_name)(some_args)