Move BVP default solver from DifferentialEquations.jl to BoundaryValueDiffEq.jl

Matches https://github.com/SciML/DifferentialEquations.jl/blob/master/src/bvp_default_alg.jl. This definitely isn't what the final form should be, but it's a step towards splitting DifferentialEquations.jl so we should follow up later on this. I think we should in this day and age make one of the FIRKs the default, but without autodiff requirements? Or auto-autodiff.

Author: ChrisRackauckas

src/BoundaryValueDiffEq.jl

@@ -13,6 +13,14 @@ using SciMLBase
 
 @reexport using ADTypes, SciMLBase
 
+function SciMLBase.__init(prob::BVProblem; kwargs...)
+    SciMLBase.__init(prob, Shooting(Tsit5()); kwargs...)
+end
+
+function SciMLBase.__solve(prob::BVProblem; kwargs...)
+    SciMLBase.__solve(prob, Shooting(Tsit5()); kwargs...)
+end
+
 include("extension_algs.jl")
 
 export MIRK2, MIRK3, MIRK4, MIRK5, MIRK6