Extension won't generate deployment manifests if the template contains a comment

[ethanshea-ms]

When I right click a deployment template that contains comments and select "Generate IoT Edge Deployment Manifest", I see an error message like the one below.

There are two problems here:

1. The error message only contains a position, and not a line/column number making the source of the problem difficult to track down.
2. The command does not accept templates which contain comments. This makes it difficult to document my deployments.

Reproducing file (deployment.template.json)

```jsonc { "modulesContent": { "$edgeAgent": { // This is a comment "properties.desired": { "modules": {}, "runtime": { "settings": { "minDockerVersion": "v1.25" }, "type": "docker" }, "schemaVersion": "1.0", "systemModules": { "edgeAgent": { "settings": { "image": "mcr.microsoft.com/azureiotedge-agent:1.0" }, "type": "docker" }, "edgeHub": { "settings": { "image": "mcr.microsoft.com/azureiotedge-hub:1.0" } }, "type": "docker", "status": "running", "restartPolicy": "always" } } } }, "$edgeHub": { "properties.desired": { "routes": { "route": "FROM /messages/* INTO $upstream" }, "schemaVersion": "1.0", "storeAndForwardConfiguration": { "timeToLiveSecs": 7200 } } } } } ```