Knots improvements

[oldremez]

1. More knots are added to cover most of the state machine actions
2. The error node is removed. Instead, conditions that fail transactions are changed into a parallelogram-type condition which fails transactions if a condition isn't met. As a bonus now we understand better if the state is changed in cases when we return to the previous state, it became more explicit
3. Check ICQ freshness is removed. We can rely on the fact it's done every time we leave a state and adding that as a separate state will make both scheme and implementation much more complex
4. Graph is prettified:
   

[ratik]

Suggested change

	let (unbond_message_relut, unbond_attrs) =
	get_unbonding_msg(deps.branch(), &env, config, &info)?;
	if let Some(unbond_message) = unbond_message_relut {
	let (unbond_message_result, unbond_attrs) =
	get_unbonding_msg(deps.branch(), &env, config, &info)?;
	if let Some(unbond_message) = unbond_message_result {

[oldremez]

Rewrote this code to pass by reference instead of returning it, looks cleaner