Removal of references to [System.Nullable[String]]

[iamcheek]

Using the Initialize-Search function instead of ConvertFrom-JSONToSearch in order to create the PSObject for search results in the following error

Replacing the references of [System.Nullable[String]] to [AllowNull()] fixes this

[iamcheek]

Steps to reproduce

PS C:\> $Query = Initialize-Query -Query "*"
PS C:\> $Search = Initialize-Search -Indices "accessprofiles" -Query $Query
InvalidOperation: C:\Users\mcheek\Documents\PowerShell\Modules\PSSailPoint\1.3.2\v3\src\PSSailpoint\Model\Search.ps1:65:9
Line |
  65 |          [System.Nullable[String]]
     |          ~~~~~~~~~~~~~~~~~~~~~~~~~
     | Unable to find type [System.Nullable[String]]. Details: GenericArguments[0], 'System.String', on 'System.Nullable`1[T]' violates the constraint of type 'T'.