Add some unit tests and add some #[allow()] statements to generated code to silence warnings

[fdlg]

This change brings in a few unit tests mainly checking that entry/exit handlers are called and that some transitions are correct

Four tests are disabled cause they're currently not passing, but left there as a reminder:

• Entry handler isn't called for first state entered upon state machine creation
• Parent entry handler isn't called when going from non-child state to child state
• Parent exit handler isn't called when going from child state to a non-chilld state outside of parent
• If child state has a even hadler for a give event, the parent's handler isn't called even if the childs handler doesn't result in a transition

We should probably track them separately