Update metadata in existing assets when the model is modified

[Aschen]

Updating an asset (or device) model metadata should automatically update corresponding assets:

• add metadata: initialize with null or the default metadata value if any
• delete metadata: remove the value

Also update assets/devices when adding a new measure and initialize the property with null

• e.g. asset.measures.newMeasure = null

Solution

• List engines

    const { result } = await this.sdk.query({
      controller: "device-manager/engine",
      action: "list"
    })

• updateByQuery on devices and assets collections

[fmauNeko]

Closed by #287.