fix: major cleanup of template left-overs and bvg v6 API update

[ndom91]

So I initially took a look at this because I noticed it was still asking me for username/password when setting up the integration, which aren't needed here obviously. Then I noticed the sensor couldn't update anymore for some reason, and it turns out theres a newer (non-deprecated) version of this API available.

So the changes I made here include:

• Removing lots of left over unnecessary stuff from the template you used, including:
  • Mentions of jsonplaceholder.typicode.com dummy JSON endpoint
  • Unnecessary username/password config flow
• Fixed a few different references to different versions of this repository so they all point to ryanbateman/bvg-sensor now
• I updated the version number everywhere to match, you had 0.3.1 in HACS, but 0.0.0 and 0.0.1 elsewhere (const.py for example), which was being rendered in the UI
• Updated the API endpoint to use the v6 transport.rest API, which should take the same arguments / return the same data, so no major changes needed here.

My final question to you is, are the binary_sensor and switch entites necessary? What are they used for? To me it looks like they are unused, can we remove them and simplify this? I think the bvg-sensor integration should just provide sensors for the status of public transit stops you want to follow, right?

Todo

• Currently still draft as I confirm I've not broken anything :joy:

[wrapper]

Hey just wanted to check if there was any plans to merge / finish this? Thanks cc @ryanbateman