network: tune waiting limits in tests

Some tests are failing on Windows due to slow runners with errors like the following:
```
2022-02-09T17:11:20.3127016Z     --- FAIL: TestGetData/transaction (1.82s)
2022-02-09T17:11:20.3127385Z         server_test.go:500:
2022-02-09T17:11:20.3127878Z             	Error Trace:	server_test.go:500
2022-02-09T17:11:20.3128533Z             	            				server_test.go:520
2022-02-09T17:11:20.3128978Z             	Error:      	Condition never satisfied
2022-02-09T17:11:20.3129479Z             	Test:       	TestGetData/transaction
```

pkg/network/server_test.go

@@ -404,7 +404,7 @@ func TestBlock(t *testing.T) {
 	b := block.New(false)
 	b.Index = 12345
 	s.testHandleMessage(t, nil, CMDBlock, b)
-	require.Eventually(t, func() bool { return s.chain.BlockHeight() == 12345 }, time.Second, time.Millisecond*500)
+	require.Eventually(t, func() bool { return s.chain.BlockHeight() == 12345 }, 2*time.Second, time.Millisecond*500)
 }
 
 func TestConsensus(t *testing.T) {
@@ -497,8 +497,8 @@ func (s *Server) testHandleGetData(t *testing.T, invType payload.InventoryType,
 
 	s.testHandleMessage(t, p, CMDGetData, payload.NewInventory(invType, hs))
 
-	require.Eventually(t, func() bool { return recvResponse.Load() }, time.Second, time.Millisecond)
-	require.Eventually(t, func() bool { return recvNotFound.Load() }, time.Second, time.Millisecond)
+	require.Eventually(t, func() bool { return recvResponse.Load() }, 2*time.Second, time.Millisecond)
+	require.Eventually(t, func() bool { return recvNotFound.Load() }, 2*time.Second, time.Millisecond)
 }
 
 func TestGetData(t *testing.T) {