fix: ensure node_exporter_binary_install_dir before copy binary

[namsic]

I'm trying to install node_exporter on a remote host with a custom node_exporter_binary_install_dir.

- hosts: all
  roles:
    - prometheus.prometheus.node_exporter
  vars:
    node_exporter_binary_local_dir: /home/namsic/downloads/node_exporter-1.6.0.linux-amd64
    node_exporter_binary_install_dir: /home/namsic/tmp

But when I ran the above playbook, I got the following result:

TASK [prometheus.prometheus.node_exporter : Propagate locally distributed node_exporter binary] ****************************************************************************************************************************************************************************************************************************************************************************
fatal: [remote001]: FAILED! => {
    "changed": false,
    "checksum": "894db4cbc1bda8d686d73f33f22c57c861836c9d",
    "msg": "Destination directory /home/namsic/tmp does not exist"
}

If there are multiple target hosts, it would be nice to automatically create the directory if it does not exist.

If these changes are not appropriate, please let me know.

Thanks.