[BUG] PPLSavedQueryClient / PPLSavedVisualizationClient have incongruent get/update API

[pjfitzgibbons]

What is the bug?
A clear and concise description of the bug.

Get API returns the "raw" object as contained in .opensearch-observability index/store.
Espcially note selected_date_range, selected_timestamp, selected_fields

    const client = new PPLSavedObjectClient(coreRefs.http!);

    const res = await client.get({ objectId: metric.savedVisualizationId });
    const currentVis = res.observabilityObjectList[0].savedVisualization;

    console.log('savedMetricToObservabilityStore', { currentVis });

==>
{
    "name": "[Metric] Average ram usage per day by windows os ",
    "description": "",
    "query": "source = opensearch_dashboards_sample_data_logs | where match(machine.os,'win')  |  stats avg(machine.ram) by span(timestamp,1d)",
    "type": "line",
    "selected_date_range": {
        "start": "now/y",
        "end": "now",
        "text": ""
    },
    "selected_timestamp": {
        "name": "timestamp",
        "type": "timestamp"
    },
    "selected_fields": {
        "text": "",
        "tokens": []
    },
    "user_configs": "{\"dataConfig\":{\"series\":[{\"label\":\"machine.ram\",\"name\":\"machine.ram\",\"aggregation\":\"avg\",\"customLabel\":\"\"}],\"dimensions\":[],\"span\":{\"time_field\":[{\"name\":\"timestamp\",\"type\":\"timestamp\",\"label\":\"timestamp\"}],\"unit\":[{\"text\":\"Day\",\"value\":\"d\",\"label\":\"Day\"}],\"interval\":\"1\"}}}",
    "sub_type": "metric"
}

.update() though requires a different object model, as indicated in the definition :

  async update(
    params: UpdateParams
  ): Promise<OSDSavedObjectUpdateResponse<VisualizationSavedObjectAttributes>> {
    const body = this.buildRequestBody({
      query: params.query,
      fields: params.fields,
      dateRange: params.dateRange,
      chartType: params.type,
      name: params.name,
      timestamp: params.timestamp,
      applicationId: params.applicationId,
      userConfigs: params.userConfigs,
      description: params.description,
      subType: params.subType,
      unitsOfMeasure: params.unitsOfMeasure,
      selectedLabels: params.selectedLabels,
    });

Especially note, the params object is expected differently :

• timestamp instead of selected_timestamp
• fields instead of selected_fields
• dateRange instead of selected_date_range

What is the expected behavior?
The following code should work without error :

    const client = new PPLSavedObjectClient(coreRefs.http!);

    const res = await client.get({ objectId: metric.savedVisualizationId });
    const currentVis = res.observabilityObjectList[0].savedVisualization;

    client.update(currentVis)

What is your host/environment?

• OS: [e.g. iOS]
• Version [e.g. 22]
• Plugins

Do you have any screenshots?
If applicable, add screenshots to help explain your problem.

Do you have any additional context?
Add any other context about the problem.

[pjfitzgibbons]

@derek-ho @mengweieric @joshuali925 @ps48

[noCharger]

@mengweieric are we still tracking 2.12 on this?