When there is no yearly backup retention policy, Get-AzSqlDatabaseLongTermRetentionPolicy returns 0 for WeekOfYear, but Azure Portal displays 'Week 1' as default and Set-AzSqlDatabaseLongTermRetentionPolicy wants a number between 1 and 52.

### Description

When there is no yearly backup retention policy, Get-AzSqlDatabaseLongTermRetentionPolicy returns 0 for WeekOfYear.
The value "0" does not make sense, as week 0 does not exist in a solar year.
Furthermore, Azure Portal displays "Week 1" as default and Set-AzSqlDatabaseLongTermRetentionPolicy wants a number between 1 and 52. This means Get-AzSqlDatabaseLongTermRetentionPolicy returns a wrong output, or at least an output that is in contradiction with Azure Portal and Set-AzSqlDatabaseLongTermRetentionPolicy.

### Issue script & Debug output

```PowerShell
$sourceServerName = "sql-source"
$sourceResourceGroup = "rg-dbsource"

foreach ($sourceDb in $sourceDatabases) {
if ($sourceDb.DatabaseName -eq "master") {
Write-Output "Skipping master DB."
continue
}

# Get the LTR policy for the current database
$ltrPolicy = Get-AzSqlDatabaseLongTermRetentionPolicy -DatabaseName $sourceDb.DatabaseName `
-ServerName $sourceServerName `
-ResourceGroupName $sourceResourceGroup

# Display the current LTR policy
Write-Output "Database: $($sourceDb.DatabaseName)"
Write-Output "Weekly Retention: $($ltrPolicy.WeeklyRetention)"
Write-Output "Monthly Retention: $($ltrPolicy.MonthlyRetention)"
Write-Output "Yearly Retention: $($ltrPolicy.YearlyRetention)"
Write-Output "Week Year Retention: $($ltrPolicy.WeekOfYear)"
}

Skipping master DB.
Database: mydb
Weekly Retention: P5W
Monthly Retention: PT0S
Yearly Retention: PT0S
Week Year Retention: 0
```

### Environment data

```PowerShell
Name Value
---- -----
PSVersion 7.4.6
PSEdition Core
GitCommitId 7.4.6
OS Microsoft Windows 10.0.22631
Platform Win32NT
PSCompatibleVersions {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion 2.3
SerializationVersion 1.1.0.1
WSManStackVersion 3.0
```

### Module versions

```PowerShell
ModuleType Version Name ExportedCommands
---------- ------- ---- ----------------
Script 4.0.2 Az.Accounts {Add-AzEnvironment, Clear-AzConfig, Clear-AzContext, Clear-AzDefault...}
Script 6.0.1 Az.Sql {Add-AzSqlDatabaseToFailoverGroup, Add-AzSqlElasticJobStep, Add-AzSqlElasticJobTarget, Add-AzSqlInstanceKeyVaultKey...}
```

### Error output

```PowerShell

```

Start by reproducing the behavior with Get-AzSqlDatabaseLongTermRetentionPolicy for a database without a yearly retention policy, then compare its WeekOfYear value with Set-AzSqlDatabaseLongTermRetentionPolicy's accepted range. Done means the getter's no-policy result is consistent with the documented 1–52 range and the Azure Portal's Week 1 default.

Written by the indexing model from the issue text.