feat(node)!: return time as Date instance

BREAKING CHANGE: Node returns time in KeyBlock and MicroBlockHeader as Date
Apply a change
```diff
-const time = new Date(
-  (await node.getTopHeader()).time,
-);
+const time = (await node.getTopHeader()).time;
```

test/integration/node.ts

@@ -122,6 +122,12 @@ describe('Node client', () => {
     }));
   });
 
+  it('returns time as Date', async () => {
+    const block = await node.getTopHeader();
+    expect(block.time).to.be.instanceOf(Date);
+    expect(block.time.getFullYear()).to.be.within(2024, 2030);
+  });
+
   it('doesn\'t remember failed version request', async () => {
     let shouldFail = true;
     class CustomNode extends Node {

tooling/autorest/node.yaml

@@ -143,6 +143,15 @@ directive:
       throw errors even for explained response with not 200 code
       https://github.com/Azure/autorest.typescript/issues/463#issuecomment-524203041
 
+  - from: openapi-document
+    where: $..properties.time
+    set:
+      type: 'integer'
+      format: 'unixtime'
+    reason: >
+      Convert time as milliseconds to dates
+      https://github.com/aeternity/aeternity/issues/4386
+
   - from: openapi-document
     where: $.components.schemas
     transform: >