Fix automatic detection of delayed and stochastic systems

[agchesebro]

Mostly a reminder for myself so that this gets implemented (not a priority right now). Need to go in and fix the way it's detected, and ideally create another function that just returns the appropriate problem type (e.g., ODEProblem, DDEProblem, SDDEProblem, etc.)

[agchesebro]

Further notes:

• Switching default Jansen-Rit to ODE #343 switches Jansen-Rit back to ODE, and creates a separate JansenRitDelayed for DDE version
• This change is mostly being done because JuliaSimCompiler doesn't support delays.
• Still need a better way to detect delayed edges during system_from_graph and update state calls then