Editable devices

- Don't select row when it's being edited.
- Add checkbox for creating calculating fields.
- Add allowed?* for devices.
- Use chart's date format.
- Make table scrollable (when the screen is too small to allow for
  required min table width)
- Don't use minified library for development. Hide divs instead of removing them.

I'm not sure if I understand. The above is looping through a sequence of sensors (coming from the "readings" vector in the API request body). It's not reading the sensor from the database. It's updating it. Not sure what is k.h.d.sensors/get-by-id supposed to be doing in this case?