Enhance inbound management by removing MaxClients property

- Removed the MaxClients property from Inbound-related data models, including InboundDto and PublishInboundCommand.
- Updated related methods and handlers to reflect the removal of MaxClients, ensuring consistent behavior across the application.
- Adjusted API documentation and frontend components to remove references to MaxClients, streamlining the inbound publishing process.
- Enhanced logging in command handlers to handle node unavailability scenarios during user actions.
- Improved database schema and migrations to align with the updated data model.

backend/tests/PnvPanel.IntegrationTests/Configs/ConfigQuotaTests.cs

@@ -88,7 +88,6 @@ public class ConfigQuotaTests(PnvPanelWebApplicationFactory factory)
                 isPublished = true,
                 displayName = "Quota inbound",
                 allowedRoleIds = new[] { userRole.Id },
-                maxClients = (int?)null,
             }
         );
         Assert.Equal(HttpStatusCode.OK, publishResponse.StatusCode);