feat: conversation.restart

[KnorpelSenf]

It should be made easy to have a conversation that lives forever without accumulating an infinite amount of data.

It rarely happens that bots actually have logic that handles thousands of updates. Instead, most bots only need a handful of them before they reset and start over.

This can currently be done using loops or recursion, but that does not clear the replay logs. It can also be done using a checkpoint, but that is tedious because it requires the checkpoint object to be created and dragged along manually.

It would be useful to have

await conversation.restart()

which restarts the conversation.

It is yet to be decided how arguments should be handled.

• Always use the original ones from the enter call
• Only use the original ones from the enter call if they are not overridden by explicit arguments passed to the restart call
• Always require arguments to the restart call