Allow referencing component schemas in component schemas

[glatzert]

Description of the Change

I added a cmdlet New-PodeOASchemaProperty which allows to create $refs to component schemas.

Related Issue

No related issue, I'm doing unsolicited PRs again - sorry.

Examples

Can be used like this:

Add-PodeOAComponentSchema -Name "ManagedOrganizationUnitConfiguration" -Schema (
    New-PodeOAObjectProperty -Properties @(
        (New-PodeOABoolProperty -Name "AllowBatchCreation"),
        (New-PodeOABoolProperty -Name "CheckForDuplicates"),
    ));

Add-PodeOAComponentSchema -Name "ManagedOrganizationalUnitsResponse" -Schema (
    New-PodeOAObjectProperty -Properties @(
        (New-PodeOAStringProperty -Name "Uuid" -Required),
        (New-PodeOAStringProperty -Name "Name" -Required),
        (New-PodeOASchemaProperty -Name "Config" -Reference "ManagedOrganizationUnitConfiguration")
    ));

Additional Context

I'm not completely sure about my changes in /private/OpenApi.ps1, but my swagger file looked correct (just a small excerpt):

"ManagedOrganizationalUnitsResponse": {
  "properties": {
    "Uuid": {
      "type": "string",
      "format": ""
    },
    "Name": {
      "type": "string",
      "format": ""
    },
    "Config": {
      "$ref": "#/components/schemas/ManagedOrganizationUnitConfiguration"
    },
}

[Badgerati]

I'm doing unsolicited PRs again - sorry

Hahah, it's all right! 😄

[Badgerati]

LGTM! :D