Tempus: Add Stepper Initial Conditions

Created by: ccober6

Adding a Stepper initial conditions has several benefits:

• Ensure that the initial SolutionState is consistent, i.e., x, xDot, and xDotDot satisfy the governing equation at the initial time.
• Currently explicit Steppers are not consistent until the next time step fills in the currentState. This change will make the SolutionState consistent within the time step.
• For explicit Steppers with a consistent SolutionState, the residual can be determined and compared to residuals from implicit Steppers. This is SPARC's main driver for this change.
• For DAEs, making the initial condition consistent is critical to obtain the correct solution.

@trilinos/tempus

Expectations

• Changes for this issue should not effect solutions.

Definition of Done

• First convert Forward Euler.
• Convert all other explicit Steppers, ERK, Leapfrog, ...
• Convert all implicit Steppers
• Passes all tests.