Revert "Add support for string response deserialization (#12910)"

This reverts commit b8524bee23.

samples/client/petstore/powershell/src/PSPetstore/Model/DogAllOf.ps1

@@ -0,0 +1,97 @@
+#
+# OpenAPI Petstore
+# This spec is mainly for testing Petstore server and contains fake endpoints, models. Please do not use this for any other purpose. Special characters: "" \
+# Version: 1.0.0
+# Generated by OpenAPI Generator: https://openapi-generator.tech
+#
+
+<#
+.SYNOPSIS
+
+No summary available.
+
+.DESCRIPTION
+
+No description available.
+
+.PARAMETER Breed
+No description available.
+.OUTPUTS
+
+DogAllOf<PSCustomObject>
+#>
+
+function Initialize-PSDogAllOf {
+    [CmdletBinding()]
+    Param (
+        [Parameter(Position = 0, ValueFromPipelineByPropertyName = $true)]
+        [String]
+        ${Breed}
+    )
+
+    Process {
+        'Creating PSCustomObject: PSPetstore => PSDogAllOf' | Write-Debug
+        $PSBoundParameters | Out-DebugParameter | Write-Debug
+
+
+        $PSO = [PSCustomObject]@{
+            "breed" = ${Breed}
+        }
+
+
+        return $PSO
+    }
+}
+
+<#
+.SYNOPSIS
+
+Convert from JSON to DogAllOf<PSCustomObject>
+
+.DESCRIPTION
+
+Convert from JSON to DogAllOf<PSCustomObject>
+
+.PARAMETER Json
+
+Json object
+
+.OUTPUTS
+
+DogAllOf<PSCustomObject>
+#>
+function ConvertFrom-PSJsonToDogAllOf {
+    Param(
+        [AllowEmptyString()]
+        [string]$Json
+    )
+
+    Process {
+        'Converting JSON to PSCustomObject: PSPetstore => PSDogAllOf' | Write-Debug
+        $PSBoundParameters | Out-DebugParameter | Write-Debug
+
+        $JsonParameters = ConvertFrom-Json -InputObject $Json
+
+        # check if Json contains properties not defined in PSDogAllOf
+        $AllProperties = ("breed")
+        foreach ($name in $JsonParameters.PsObject.Properties.Name) {
+            if (!($AllProperties.Contains($name))) {
+                throw "Error! JSON key '$name' not found in the properties: $($AllProperties)"
+            }
+        }
+
+        if (!([bool]($JsonParameters.PSobject.Properties.name -match "breed"))) { #optional property not found
+            $Breed = $null
+        } else {
+            $Breed = $JsonParameters.PSobject.Properties["breed"].value
+        }
+
+        $PSO = [PSCustomObject]@{
+            "breed" = ${Breed}
+        }
+
+        return $PSO
+    }
+
+}
+