Incorrect error message

## Description
Two issues:

1. Customer was able to create a cluster without providing -SkuName.
- In cluster create REST, you are required to provide both -SkuName and -SkuCapacity
- In cluster update, when updating capacity, you need to provide both -SkuName and -SkuCapacity

2. We have a case where customer configured CMK and then updated it with incorrect capacity value and got generic error message:
"Update-AzOperationalInsightsCluster: Operation returned an invalid status code 'BadRequest'"

Instead of the one returned from the API:
{
"error": {
"code": "BadRequest",
"message": "CapacityReservationLevel must be in the range of 1000-3000. Contact us to increase the limit LAIngestionRate@microsoft.com"
}
}

## Steps to reproduce

Update-AzOperationalInsightsCluster -ResourceGroupName {rg-name} -ClusterName {cluster-name} -SkuName CapacityReservation -SkuCapacity 1000

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## Environment data

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## Module versions

```powershell

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## Debug output

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## Error output

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