Much improved auto-detection of frigate camera name

[dermotduffy]

• Users who needed to manually set frigate_camera_name may no longer need to do so.
• Use the entity unique_id to autodetect the true camera name. As that value cannot be changed by the user, that's substantially more likely to contain the true Frigate camera name. Fallback to the old behavior if the unique_id cannot be retrieved from HomeAssistant.
• Closes Improve automatic detection of Frigate camera name #84

[github-actions]

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