[Infra Monitoring UI] update metrics-explorer-view interfaces to have strict types for validation

[neptunian]

📓 Summary

As part of the road to versioned HTTP APIs:

3. HTTP APIs have strict input validation

the API should not accept any data that could cause application code to throw exceptions or otherwise fail. E.g. given an input field value. If your application code divides by value you need to add value != 0 validation or explicitly handle that case.

The metrics-explorer-view so-attribs interface does not type all the necessary fields that are required for the app to function properly nor does the HTTP API interface.

Eg: posting to API with a number instead of a string in options.metrics.field

POST http://localhost:5601/api/infra/metrics-explorer-view
{
  "attributes": {
        "options": {
            "aggregation": "avg",
            "metrics": [
                {
                    "aggregation": "avg",
                    "field": 1,
                    "color": "color0"
                }
            ],
            "source": "default"
        },
...
}

Response status: 201 created

App after navigating to new saved view:

✔️ Acceptance criteria

• The /api/infra/metrics-explorer-view route should have strict input validation
• Loading a view should not cause the app to fail because of some input

💡 Notes

• Updating the runtime types should be sufficient in resolving this issue
• so-attribs interface and HTTP API interface must remain separate and should not refer to each other even if they are the same

[elasticmachine]

Pinging @elastic/infra-monitoring-ui (Team:Infra Monitoring UI)

[roshan-elastic]

@neptunian - checking whether this would make sense to do in 8.10? I moved this to the top of the 'ready' column - I can label as 8.10 to give it a bit more visibility.

[neptunian]

Sure. It has no dependencies and should be a straightforward task.