Remove openexchangerates sensor rounding

[MartinHjelmare]

Breaking change

Remove rounding of the exchange rate.

Exchange rates are generally more sensitive to small changes and some quotes need many decimal numbers to be accurate. The Open Exchange Rates service will provide different number of significant digits for different quotes. You can change the display precision or use a template sensor if you want to customize the rounding of the value.

Proposed change

• Remove rounding of the exchange rate.
• Exchange rates are generally more sensitive to small changes and some quotes need many decimal numbers to be accurate. The Open Exchange Rates service will provide different number of significant digits for different quotes. We should just use what they return. The user can change the display precision or use a template sensor if they want to customize rounding.

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)
• Deprecation (breaking change to happen in the future)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes Open Exchange Rate Integration has a 4 decimal limit, which prevents use of various metals/currencies #103945
• This PR is related to issue:
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
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[joostlek]

Can't we set the suggested_display_precision to 4 on the sensor to avoid changing the UI?

[MartinHjelmare]

I don't think that's a good idea as I've tried to explain in the PR description. Here's an example how that would look for BTC.