Fix blobby multi-word state on flow run bar chart popover

[collincchoy]

Users can return their own custom name/message for a flow run's state.

For example via:

@flow
def hello_world():
    return State(
        type=StateType.COMPLETED,
        name="My custom name",
        message="My custom message.",
    )

The above message renders in a little goofily for the flow run bar chart popover though which this PR addresses.

Before |-> After