PTE solver methods should be able to take different array types

[jhp-lanl]

Currently, the PTE solver methods all assume there are only three (four if you include Real) types: 1) the EOS array type, 2) the Real array type, and 3) the lambda array type. The issue I'm encountering is that a common design pattern is to mix things like Kokkos views with Kokkos subviews. Although these behave the same (after I wrap them in a square bracket operator), they are different types that are not implicitly convertible.

I would request that we allow the PTE solver methods to have distinct template types for at least the arrays being passed. In a C++14 world without CTAD, I understand the desire to keep template parameter lists short, but now we can just deduce the types easily and I don't believe there's a real reason to limit the number of template parameters for a class.

So this change would also probably require (for usability) adding CTADs to the PTE solver methods.

As a bonus, I think there is a way to also achieve backwards compatibility if that is desired. Here is an example that ChatGPT came up with. Mind you it would involve a second layer of inheritance...

// primary declaration
template<class ObjArr, class... Ts>
class MyClass;

// 5-arg base implementation
template<class ObjArr, class Real1, class Real2, class Real3, class CacheArr>
class MyClass<ObjArr, Real1, Real2, Real3, CacheArr>
{
  ObjArr&   obj_arr_;
  Real1&    real1_;
  Real2&    real2_;
  Real3&    real3_;
  CacheArr& cache_;

public:
  MyClass(ObjArr& o, Real1& r1, Real2& r2, Real3& r3, CacheArr& c)
    : obj_arr_(o), real1_(r1), real2_(r2), real3_(r3), cache_(c) {}
};

// 3-arg legacy spelling delegates to 5-arg via inheritance
template<class ObjArr, class Real, class CacheArr>
class MyClass<ObjArr, Real, CacheArr>
  : public MyClass<ObjArr, Real, Real, Real, CacheArr>
{
  using Base = MyClass<ObjArr, Real, Real, Real, CacheArr>;
public:
  using Base::Base;
};

// CTAD
template<class ObjArr, class Real1, class Real2, class Real3, class CacheArr>
MyClass(ObjArr&, Real1&, Real2&, Real3&, CacheArr&)
  -> MyClass<ObjArr, Real1, Real2, Real3, CacheArr>;

Tagging @jonahm-LANL @Yurlungur and @adamdempsey90