Fix citybikes

[MartinHjelmare]

Breaking Change:

N/A

Description:

• Move asyncio condition to instance from class, to be able to pass in
  loop.
• Avoid not needed side effects in init methods.
• Clean up.

Related issue (if applicable):
fixes #16523

Example entry for configuration.yaml (if applicable):

sensor:
  - platform: citybikes
    network: velib
    stations:
      - 19008
  - platform: citybikes
    network: velib
    stations:
      - 19001

Checklist:

• The code change is tested and works locally.
• Local tests pass with tox. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.