Added label to power port module

[sapergus]

Related Issue

No related issues.

New Behavior

Added 'label' as a none required option to netbox_power_port module.
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Contrast to Current Behavior

Possible to add a label to a power port in NetBox.
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Discussion: Benefits and Drawbacks

We use NetBox in my organisation and I need to be able to create labels for powerports.
Since the option to add a label is optional it should not be a problem with backward compatibility.
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Changes to the Documentation

Added a description of the label option in plugins/modules/netbox_power_port.py and generated a new version of
docs/plugins/netbox_power_port_module.rst.
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Proposed Release Note Entry

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Double Check

• [ x] I have read the comments and followed the CONTRIBUTING.md.
• [ x] I have explained my PR according to the information in the comments or in a linked issue.
• [ x] My PR targets the devel branch.

[sc68cal]

The markdown docs are automatically generated I believe, so your change should only just be to the netbox_power_port.py file.