#5064 Add creation timestamp to inflight orders

We need to start registering the orders creation timestamp as a separate field. Currently orders take that information from the last component of the order id. But there is a requirement to change the order id generation method, to ensure its uniqueness, and the creation timestamp will not be part of the order id any more in the future.

This PR adds the creation timestamp in the inflight orders. It also changes the calculation of the orders age that was done by taking the creation timestamp from the client order id. Applies the same changes to the hanging orders.

Modifies the JSON serialization/deserialization of orders to include the creation timestamp.

Changes the market recorder to use the new timestamp when storing the creation time instead of using the timestamp when the event was received (the previous logic).

Link: https://github.com/hummingbot/hummingbot/pull/5064