fix kokkosinlinefunction to support attributes

[fnrizzi]

The current impl of kokkosinlinefunction was only partially working.
This PR fixes it so that we can prepend static, etc

.. role:: cppkokkos(code)
    :language: cppkokkos

.. cppkokkos:kokkosinlinefunction:: double foo1(int const a);

.. cppkokkos:kokkosinlinefunction:: template<class T> double foo1(int const a);

.. cppkokkos:kokkosinlinefunction:: static double foo2(int const a);

.. cppkokkos:kokkosinlinefunction:: explicit constexpr double foo(int a = 0);

Renders as:

[ajpowelsnl]

Looks good

[nmm0]

LGTM!