API change: Delta as a first parameter in process functions

[SirPigeonz]

Removes delta from Blackboard and adds delta to:

• tick(delta, actor, blackboard)
• _on_update(delta, actor, blackboard)
• _on_transition(delta, actor, blackboard)

Fixes: #31

[SirPigeonz]

I should have first clean up indentations :/ it's hard to read changes now..."

[ThePat02]

I should have first clean up indentations :/ it's hard to read changes now...

Don't worry, VS Code didn't even show tabs as changes!