feat: add Invoke-ListResellerRelationshipLink function for retrieving reseller relationship links

implements KelvinTegelaar/CIPP#5963

Author: JohnDuprey

Modules/CIPPHTTP/Public/Entrypoints/HTTP Functions/Invoke-ListResellerRelationshipLink.ps1

@@ -0,0 +1,37 @@
+function Invoke-ListResellerRelationshipLink {
+    <#
+    .FUNCTIONALITY
+        Entrypoint,AnyTenant
+    .ROLE
+        Tenant.Relationship.Read
+    #>
+    [CmdletBinding()]
+    param($Request, $TriggerMetadata)
+
+    $StatusCode = [HttpStatusCode]::OK
+    $Body = @{}
+
+    # Get the indirect reseller relationship invite link
+    try {
+        $RelationshipRequest = New-GraphGetRequest -uri 'https://api.partnercenter.microsoft.com/v1/customers/relationshiprequests?dualRoleIndirectRelationship=false' -scope 'https://api.partnercenter.microsoft.com/.default' -NoAuthCheck $true
+        $Body.inviteUrl = $RelationshipRequest.url
+    } catch {
+        $Body.inviteUrl = $null
+        $Body.inviteUrlError = "Failed to retrieve relationship invite link: $($_.Exception.Message)"
+        Write-Information "ListResellerRelationshipLink: Failed to get invite URL - $($_.Exception.Message)"
+    }
+
+    # Get indirect providers (for Tier 2 / indirect resellers)
+    try {
+        $RelationshipsResponse = New-GraphGetRequest -uri 'https://api.partnercenter.microsoft.com/v1/relationships?relationship_type=IsIndirectResellerOf' -scope 'https://api.partnercenter.microsoft.com/.default' -NoAuthCheck $true
+        $Body.indirectProviders = @($RelationshipsResponse.items)
+    } catch {
+        $Body.indirectProviders = @()
+        Write-Information "ListResellerRelationshipLink: Failed to get indirect providers - $($_.Exception.Message)"
+    }
+
+    return [HttpResponseContext]@{
+        StatusCode = $StatusCode
+        Body       = $Body
+    }
+}