Add Twitch subscription and additional stats

[Poeschl]

Breaking change

Proposed change

This change adds more stats about the specified streamer as well as the opportunity to check follow and subscription status.
There are also tests for all functionalities

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

Example entry for configuration.yaml:

# Example configuration.yaml
sensor:
  platform: twitch
  client_id: <client_id>
  oauth_token: <oauth_token>
  channels:
    - gronkh

To get the oauth_token take a look to the doc PR.

Additional information

• Link to documentation pull request: Adjust twitch integration configuration home-assistant.io#11853

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
• The code has been formatted using Black (black --fast 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.
• Untested files have been added to .coveragerc.

The integration reached or maintains the following Integration Quality Scale:

• No score or internal
• 🥈 Silver
• 🥇 Gold
• 🏆 Platinum

[Poeschl]

I wrote tests to ensure the integration is working correctly, but I can't get the mocks to work in the correct way.
It would be nice, to have some help with them.

They work if executed one by one but not when executed together.

[springstan]

LGTM ✌ just one small suggestion:

[springstan]

You will need to adjust the tests as well I think :)

[Poeschl]

Done :D

[MartinHjelmare]

We don't set this state attribute. Setting the name property is enough.

[ghost]

I hope it's appropriate to comment here, I wanted to bring to light an issue I have posted that may be relevant to implement during this change. #32050 Thank you.