Add Display Precision to Meter Sensor

[cabberley]

Checklist

• I have filled out the template to the best of my ability.
• This only contains 1 feature request (if you have multiple feature requests, open one feature request for each feature request).
• This issue is not a duplicate feature request of previous feature requests.

Is your feature request related to a problem? Please describe.

By Default the source sensors display precision is used.

Describe the solution you'd like

Add option when creating Meter Sensor to set dispaly precision.

Describe alternatives you've considered

NA

Additional context

NA

[HiDiHo01]

Display Precision is set fine and you can adjust it yourself