Add more labels to Prometheus metrics

[cedi]

This commit adds additional labels to the Prometheus metrics to make aggregation and querying in PromQL easier.

The added labels include:

• platform - To be able to query based on the platform which is providing the entity
• area - The normalized_name of the area in which the entity is in
• categories - the dictionary of categories assigned to the entity

This is my first rough draft and it'll probably take me a bit longer to validate everything still works than it took me to make those initial code changes. Feel free to point out any glaring mistakes while I'm working on testing.

Breaking change

Proposed change

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)
• Deprecation (breaking change to happen in the future)
• 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.
• I have followed the development checklist
• I have followed the perfect PR recommendations
• The code has been formatted using Ruff (ruff format homeassistant tests)
• Tests have been added to verify that the new code works.

If user exposed functionality or configuration variables are added/changed:

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

If the code communicates with devices, web services, or third-party tools:

• The manifest file has all fields filled out correctly.
  Updated and included derived files by running: python3 -m script.hassfest.
• New or updated dependencies have been added to requirements_all.txt.
  Updated by running python3 -m script.gen_requirements_all.
• For the updated dependencies - a link to the changelog, or at minimum a diff between library versions is added to the PR description.

To help with the load of incoming pull requests:

• I have reviewed two other open pull requests in this repository.

[home-assistant]

Hi @cedi

It seems you haven't yet signed a CLA. Please do so here.

Once you do that we will be able to review and accept this pull request.

Thanks!

[home-assistant]

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

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[knyar]

Thank you for your interest in improving the Prometheus integration. Please note that additional labels were being discussed in #94538 and @jzucker2 has been working on a PR as well (#128607) - you might want to coordinate your efforts with them.