Fix unique_id issue on onewire config entries

[epenet]

Proposed change

The unique_id is available on config entries in SysBus mode, but not in OWServer mode, yet it is used to populate hass.data[DOMAIN]. This causes a conflict when multiple OWServer entries are configured.

This PR instead uses entry_id to populate hass.data[DOMAIN]

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue:
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
• Local tests pass. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.
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• Tests have been added to verify that the new code works.

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• Documentation added/updated for www.home-assistant.io

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  Updated and included derived files by running: python3 -m script.hassfest.
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  Updated by running python3 -m script.gen_requirements_all.
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[probot-home-assistant]

Hey there @garbled1, mind taking a look at this pull request as its been labeled with an integration (onewire) you are listed as a codeowner for? Thanks!
_{^{(message by CodeOwnersMention)}}

[epenet]

cc @klona

[MartinHjelmare]

Looks good!

[MartinHjelmare]

Should we tag this for a patch release?

[epenet]

Should we tag this for a patch release?

Yes please - it was reported to me on 2021.4.6 so it would be good to fix in 2021.5