Inline tests and distribute with package

[rikroe]

Proposed change

Move tests inline and distribute them with the package.

While not the default way, it is suggested by pytest's good integration practices.

With inlined tests and distributed responses, we can reuse them in HA testing. This makes end-to-end testing of HA functionality much easier and we don't have to copy/adjust the code that much.

Type of change

• [ ] Bugfix (non-breaking change which fixes an issue)
• [ ] New feature (which adds functionality to this library)
• [ ] Breaking change (fix/feature causing existing functionality to break)
• [x] 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:

Checklist

• [x] The code change is tested and works locally.
• [x] Tests have been added to verify that the new code works.

[codecov[bot]]

Codecov Report

Patch and project coverage have no change.

Comparison is base (e5d6e18) 100.00% compared to head (d832d65) 100.00%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #552 +/- ## ========================================= Coverage 100.00% 100.00% ========================================= Files 18 18 Lines 1504 1504 ========================================= Hits 1504 1504 ``` | Flag | Coverage Δ | | |---|---|---| | 3.10 | `100.00% <ø> (ø)` | | | 3.11 | `100.00% <ø> (ø)` | | | 3.7 | `100.00% <ø> (ø)` | | | 3.8 | `100.00% <ø> (ø)` | | | 3.9 | `100.00% <ø> (ø)` | | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=bimmerconnected#carryforward-flags-in-the-pull-request-comment) to find out more.

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