[BUG] Extending SQLVM with additional data disks not working as expected

### API Spec link

https://github.com/Azure/azure-rest-api-specs/tree/main/specification/sqlvirtualmachine/resource-manager/Microsoft.SqlVirtualMachine/stable/2023-10-01

### API Spec version

2023-10-01

### Describe the bug

With an existing sql vm with the following storage configuration:

```
"storageConfigurationSettings": {
"diskConfigurationType": "NEW",
"sqlDataSettings": {
"defaultFilePath": "F:\\SQLData",
"luns": [
0
]
},
"sqlLogSettings": {
"defaultFilePath": "F:\\SQLLog",
"luns": [
0
]
},
"sqlSystemDbOnDataDisk": false,
"sqlTempDbSettings": {
"dataFileCount": 8,
"dataFileSize": 256,
"dataGrowth": 512,
"defaultFilePath": "F:\\SQLTemp",
"logFileSize": 512,
"logGrowth": 512,
"luns": [
0
]
},
"storageWorkloadType": "OLTP"
},
```

When the following PUT request is sent containing the following storage configuration, we get an error that only one disk can be extended at a time:

```
"storageConfigurationSettings": {
"diskConfigurationType": "EXTEND",
"sqlDataSettings": {
"defaultFilePath": "F:\\SQLData",
"luns": [
1
]
},
"sqlLogSettings": {
"defaultFilePath": "F:\\SQLLog",
"luns": [
0
]
},
"sqlSystemDbOnDataDisk": false,
"sqlTempDbSettings": {
"dataFileCount": 8,
"dataFileSize": 256,
"dataGrowth": 512,
"defaultFilePath": "F:\\SQLTemp",
"logFileSize": 512,
"logGrowth": 512,
"luns": [
0
]
},
"storageWorkloadType": "OLTP"
},
```

When sqlTempDbSettings and sqlLogSettings are omitted from the request, we get an error stating "Original Error: Code="InvalidArgument" Message="Invalid argument 'DefaultFilePath'.".

When sqlTempDbSettings, sqlLogSettings and sqlDataSettings.DefaultFilePath are omitted from the PUT request, the extension happens successfully, however in a subsequent GET request our storage configuration now looks like:

```
"storageConfigurationSettings": {
"sqlDataSettings": {
"luns": [
1
]
},
"sqlLogSettings": {},
"sqlTempDbSettings": {},
"sqlSystemDbOnDataDisk": false,
"diskConfigurationType": "EXTEND"
},
```

### Expected behavior

Expect to be able to extend data disk and maintain existing storage configuration

### Actual behavior

Existing storage configuration must be omitted from the request and cannot be retrieved from subsequent GETs

### Reproduction Steps

1. Create an SQLVM with storage configuration
2. Send a PUT request with additional data disk

### Environment

_No response_