add nodes endpoint

- add NodesController
  - add NodesEndpoint
  - add NodesControllerTest
  - add NodesController
  - add nodes.http

- add NodeEntity toNodesResponse in Mapping.kt

- add getNodes to NodeService

- add findAll to NodeRepository

src/main/kotlin/ltd/hlaeja/util/Mapping.kt

@@ -12,6 +12,7 @@ import ltd.hlaeja.library.deviceRegistry.Device
 import ltd.hlaeja.library.deviceRegistry.Devices
 import ltd.hlaeja.library.deviceRegistry.Identity
 import ltd.hlaeja.library.deviceRegistry.Node
+import ltd.hlaeja.library.deviceRegistry.Nodes
 import ltd.hlaeja.library.deviceRegistry.Type
 import ltd.hlaeja.library.deviceRegistry.Types
 import org.springframework.http.HttpStatus.EXPECTATION_FAILED
@@ -75,3 +76,11 @@ fun DeviceEntity.toDevicesResponse(): Devices.Response = Devices.Response(
     type,
     timestamp,
 )
+
+fun NodeEntity.toNodesResponse(): Nodes.Response = Nodes.Response(
+    id ?: throw ResponseStatusException(EXPECTATION_FAILED),
+    timestamp,
+    client,
+    device,
+    name,
+)