add strip_solution tests

[jClugstor]

Checklist

• [ x] Appropriate tests were added
• [ x] Any code changes were done in a way that does not break public API
• [ x] All documentation related to code changes were updated
• [ x] The new code follows the contributor guidelines, in particular the SciML Style Guide and COLPRAC.
• [ x] Any new documentation only uses public API

[jClugstor]

has_lazy_interpolation should extend the one in SciMLBase right? Right now the lazy interpolation check doesn't error since it's using the general dispatch in SciMLBase, instead of the one in OrdinaryDiffEq, SciMLBase.has_lazy_interpolation(alg::Union{Vern6, Vern7, Vern8, Vern9}) = true. I think I might need to reexport something?

[ChrisRackauckas]

You shouldn't need to export anything. If you overload it properly (like what you show) that should be fine.

[ChrisRackauckas]

Test failure

[ChrisRackauckas]

For TRBDF2, check the nlsolver is stripped https://github.com/SciML/OrdinaryDiffEq.jl/blob/master/lib/OrdinaryDiffEqSDIRK/src/sdirk_caches.jl#L15

[jClugstor]

Do I need to set nlsolver to nothing for any cache that has it as a field?

[ChrisRackauckas]

yes