Bitpanda (non-pro) pricing data API

[RichieGKB]

The Bitpanda functionality is not given anymore.

• The format of the CSV has changed
• The pricing history API is trying to be fetched for Bitpanda. This is a Pro functionality only. But it is not needed anyways, as the CSV files contain all the necessary price data.

Edit:
I figured out, that this only appears when unrealized profits are enabled.
Bitpanda offers a new, non-pro, and free accessible API to fetch pricing data:
https://api.bitpanda.com/v1/ticker

[wullxz]

Additionally, bitpanda pro is now "One Trading". The api does still exist apparently but is available under a different address: https://docs.onetrading.com/#one-trading-api

[wullxz]

I'm currently creating a PR for the CSV format change. A mention should pop up here once I'm done with the PR.

As for the API calls:

• The ticker API sadly only shows current info and no historical info
• The One Trading API (ex Bitpanda Pro) doesn't offer price data for all assets that Bitpanda (Pro) had but can still be used. I've included changes to use that API as best as possible in my PR. A different solution might be welcome though.