Late-import some modules required via conftest

[akx]

Proposed change

This PR gently adjusts some imports to happen within late and/or within TYPE_CHECKING blocks to make it possible to run tests for a given component without requiring that many unnecessary dependencies.

This does not fully fix the situation; sqlalchemy and fnvhash are required by recorder, which was much harder to untangle than these, but those are still not automatically installed in e.g. a GitHub Codespace (they're e.g. not in requirements_test.txt).

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)
• [x] Code quality improvements to existing code or addition of tests

Checklist

• [x] The code change is tested and works locally.
• [ ] Local tests pass. Your PR cannot be merged unless tests pass
• [x] There is no commented out code in this PR.
• [x] I have followed the development checklist
• [x] The code has been formatted using Black (black --fast homeassistant tests)
• [ ] Tests have been added to verify that the new code works.

To help with the load of incoming pull requests:

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

[home-assistant[bot]]

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[home-assistant[bot]]

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

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[akx]

As per @epenet's request, split into #81791 and #81790.