Add new API call placeholders

[fedjo]

Add API calls that work with external parcel_id

You can use an updated API call name that follows best practices. Example

/api/v1/eto?parcelId=&?startDate=&endDate=

/api/v1/soilmoisture?parcelId=&?startDate=&endDate=

[vlf-stefan-drobic]

Done for ETo, unsure for the soil-moisture.
@prske

[prske]

Also done for soil moisture.