[Fix] "false" utility network load problem

[yo1995]

Description

This PR fixes an issue in the Trace utility network sample.

In the original PR, when the sample opens, a computed property private var network: UtilityNetwork? { map.utilityNetworks.first } tries to get the first utility network from the web map. However, because the web map is not explicitly loaded, network can become nil occasionally, depending on the load timing of the map.

This leads to the problem in 4401 where the network?.makeElement(arcGISFeature: feature) call silently fails. A status message was added in #248 to show the error.

After discussing with Jen, both the web map and the network need to be loaded. Only loading the map is not enough; only loading the network doesn't guarantee the map to be present either. Once the map is loaded, we can safely assume the utility network's description is available.

Linked Issue(s)

• swift/issues/4401
• [New] Trace utility network #130 (comment)

How To Test

• On v.next, sometimes you cannot add element to the utility network
• With the fixes on this branch, the sample is correct

[dg0yal]

let's get this moving

[saratchandrakarumuri]

Tested this multiple times with the fix and identify is working as expected on UN.

[saratchandrakarumuri]

Tested this multiple times with the fix and identify is working as expected on UN.

[yo1995]

Thank you!