Reorganized bindings components to map ADIOS2 core classes
Using cmake FortranCInterface to automatically resolve name mangling

BPWrite_c -> ctypes
XMLConfigTest.TwoIOs -> Test BP Writer 1

Subroutine based, calls the C bindings using opaque pointers
Working helloBPWriter_f in MPI and nonMPI examples
Separated MPI and nonMPI interfaces in Fortran and C
Passing character array by trimming and adding char(0) null terminated

To do:
Add testing