Do not show an empty component name on MQTT device subentries not as None if it is not set

[jbouwh]

Proposed change

With #144289 the entity name is explitly set to None if it has been left empty. Side effect was that in some dialogs this will display None instead of the intended -.

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
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• Breaking change (fix/feature causing existing functionality to break)
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Additional information

• This PR fixes or closes issue: fixes #
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[home-assistant]

Hey there @emontnemery, @bdraco, mind taking a look at this pull request as it has been labeled with an integration (mqtt) you are listed as a code owner for? Thanks!

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[jbouwh]

Thanks!