adding sql database module

BenchPress/Helpers/Azure/SqlDatabase.psm1

@@ -0,0 +1,12 @@
+function Get-SqlDatabase([string]$databaseName, [string]$serverName, [string]$resourceGroupName) {
+  $resource = Get-AzSqlDatabase -ResourceGroupName $resourceGroupName -ServerName $serverName -DatabaseName $databaseName
+  return $resource
+}
+
+function Get-SqlDatabaseExists([string]$databaseName, [string]$serverName, [string]$resourceGroupName) {
+  $resource = Get-SqlDatabase $databaseName $serverName $resourceGroupName
+  return ($null -ne $resource)
+}
+
+Export-ModuleMember -Function `
+  Get-SqlDatabase, Get-SqlDatabaseExists