replace numerous subtypes in smaller classes with a traits class

[martinjrobins]

many smaller function objects have a long list of subtypes to various types that they need, often based on templated Particles, Elements or Query types. Should make a traits class that can get all these subtypes, would save a lot of lines of code

Create:

• ContainerTraits<Particles<...>>

Use in:

• detail::integrate_chebyshev
• detail::integrate_over_element
• detail::zero_kernel