Add Expiry Indicator functionality with configuration and command set

- Implemented ExpiryItemService to manage expiry date logic for list items.
- Created ExpiryModels to define types and structures for expiry configurations and rules.
- Added RestError utility for handling API response errors.
- Developed ExpiryIndicatorFieldCustomizer to display expiry information in list views.
- Introduced ExpiryIndicatorCommandSet for extending expiry dates and managing settings.
- Added settings dialog for configuring expiry settings.
- Implemented localization support for English and German languages.
- Added TypeScript configuration files for project setup.
- Included TSLint configuration for code quality enforcement.

scripts/Disable-ExpiryIndicator.ps1

@@ -0,0 +1,44 @@
+[CmdletBinding(SupportsShouldProcess = $true)]
+param(
+    [Parameter(Mandatory = $true)]
+    [string]$SiteUrl,
+
+    [Parameter(Mandatory = $true)]
+    [string]$ListTitle,
+
+    [Parameter(Mandatory = $true)]
+    [string]$ExpiryFieldInternalName,
+
+    [Guid]$FieldCustomizerComponentId = 'a555f4fc-d6a6-4421-8189-457449d9bbde'
+)
+
+$isapiPath = Join-Path ([Environment]::GetFolderPath('CommonProgramFiles')) 'microsoft shared\Web Server Extensions\16\ISAPI'
+Add-Type -Path (Join-Path $isapiPath 'Microsoft.SharePoint.Client.Runtime.dll')
+Add-Type -Path (Join-Path $isapiPath 'Microsoft.SharePoint.Client.dll')
+
+$context = New-Object Microsoft.SharePoint.Client.ClientContext($SiteUrl)
+$context.Credentials = [System.Net.CredentialCache]::DefaultNetworkCredentials
+
+try {
+    $list = $context.Web.Lists.GetByTitle($ListTitle)
+    $field = $list.Fields.GetByInternalNameOrTitle($ExpiryFieldInternalName)
+    $context.Load($list)
+    $context.Load($field)
+    $context.ExecuteQuery()
+
+    if ($field.ClientSideComponentId -ne $FieldCustomizerComponentId) {
+        throw "Das Feld '$($field.InternalName)' ist nicht mit dem erwarteten ExpiryIndicator-Field-Customizer verbunden."
+    }
+
+    if ($PSCmdlet.ShouldProcess("$($list.Title)/$($field.InternalName)", 'Field-Customizer-Verknüpfung entfernen')) {
+        $field.ClientSideComponentId = [Guid]::Empty
+        $field.ClientSideComponentProperties = ''
+        $field.Update()
+        $context.ExecuteQuery()
+        Write-Host "ExpiryIndicator-Verknüpfung wurde entfernt. Feld und Daten bleiben unverändert."
+    }
+}
+finally {
+    $context.Dispose()
+}
+

scripts/Enable-ExpiryIndicator.ps1

@@ -0,0 +1,43 @@
+[CmdletBinding()]
+param(
+    [Parameter(Mandatory = $true)]
+    [string]$SiteUrl,
+
+    [Parameter(Mandatory = $true)]
+    [string]$ListTitle,
+
+    [Parameter(Mandatory = $true)]
+    [string]$ExpiryFieldInternalName,
+
+    [Guid]$FieldCustomizerComponentId = 'a555f4fc-d6a6-4421-8189-457449d9bbde'
+)
+
+$isapiPath = Join-Path ([Environment]::GetFolderPath('CommonProgramFiles')) 'microsoft shared\Web Server Extensions\16\ISAPI'
+Add-Type -Path (Join-Path $isapiPath 'Microsoft.SharePoint.Client.Runtime.dll')
+Add-Type -Path (Join-Path $isapiPath 'Microsoft.SharePoint.Client.dll')
+
+$context = New-Object Microsoft.SharePoint.Client.ClientContext($SiteUrl)
+$context.Credentials = [System.Net.CredentialCache]::DefaultNetworkCredentials
+
+try {
+    $list = $context.Web.Lists.GetByTitle($ListTitle)
+    $field = $list.Fields.GetByInternalNameOrTitle($ExpiryFieldInternalName)
+    $context.Load($list)
+    $context.Load($field)
+    $context.ExecuteQuery()
+
+    if ($field.InternalName -ne $ExpiryFieldInternalName) {
+        Write-Warning "Das Feld wurde über seinen Anzeigenamen gefunden. Für eine stabile Konfiguration sollte der interne Name '$($field.InternalName)' verwendet werden."
+    }
+
+    $field.ClientSideComponentId = $FieldCustomizerComponentId
+    $field.ClientSideComponentProperties = '{}'
+    $field.Update()
+    $context.ExecuteQuery()
+
+    Write-Host "ExpiryIndicator wurde für '$($list.Title)' an '$($field.InternalName)' gebunden."
+}
+finally {
+    $context.Dispose()
+}
+