Add strip_cache for DECache

[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

Additional context

Add any other context about the problem here.

[ChrisRackauckas]

Create a test that catches this.

[ChrisRackauckas]

why is this needed here? Isn't it just internal to OrdinaryDiffEq?

[jClugstor]

I wasn't sure if there were other interpolation types in SciMLBase that would have caches.
Is it better to just put

function strip_cache(cache::OrdinaryDiffEqCache)
    # most caches don't have jac_config or grad_config
    cache
end

in to OrdinaryDiffEq?

[ChrisRackauckas]

You define a special strip_interpolation in OrdianryDiffEq, and that will have a function in there to strip caches, and then that is defined as just a helper which uses knowledge of how caches in OrdinaryDiffEq work. I don't see that as generic at all though.

[jClugstor]

I was thinking something like this:

function SciMLBase.strip_interpolation(id::InterpolationData)
    cache = id.cache
    
    cache = strip_cache(cache)

    InterpolationData(nothing, id.timeseries,
        id.ts,
        id.ks,
        id.alg_choice,
        id.dense,
        cache,
        id.differential_vars,
        id.sensitivitymode)
end

function strip_cache(cache::OrdinaryDiffEqCache)
    # most caches don't have jac_config or grad_config
    cache
end

and then I can define strip_cache specifically for the cache types that need jac_config and grad_config to be taken out.