Ordered `OnExit` and `OnEnter`

[MiniaczQ]

What problem does this solve or what need does it fill?

Currently OnExit and OnEnter aren't ordered in relation to the state dependency graph.
This is a problem when parent state transition prepares e.g. resources for substates, but the OnEnter(Substate) runs first.

What solution would you like?

• Order OnExit to run from graph leaf-states to root-states.
• Keep OnTransition in arbitrary order.
• Order OnEnter to run from graph root-states to leaf-states.

This can either be done by adding after conditions during state installation or as part of StateRegistry, a separate feature.

What alternative(s) have you considered?

None that seem reasonable.

Additional context

This could be considered a bug to some degree.

Working example, entering Settings will crash or not, depending on the system order that was decided during startup.

[MiniaczQ]

Note that the fix with after will backfire on custom schedule runners, which
while still ordered AFTER their parent states, won't have the ordering to run BEFORE dependent states
(since those too use after and will only register them after built-in runners)

[lee-orr]

@MiniaczQ @alice-i-cecile - working on a potential solution