Redesign the logic for C binding test with google framework.
In the future we should also add validation for binding tests.

Remove meaningless code(AddTransport which is not implemented yet) in
HDF5 test as well.

In this PR, I extend HDF5 native reader so that now hdf5 tests can read data
by selection(so called hyperslab selection in hdf5).

This PR also add testing for bp file name with path.

Since collective meta generation has not landed yet, I have to use
same attribute for all processes. Ideally attribute per process
should be unique to each other for testing purpose.

Testing and Examples issues after merging with master for conflicts
Fixing non-MPI issue
C enums and Fortran parameters now compatible

First working examples
To do:
Resolve conflicts
Add tests after merging with current master

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

TO achieve this goal, GoogleTest.cmake is extended to allow
exec_wrapper and SmallTestData.h now would generate data based on
step&world_rank&world_size.
ADIOS2ADIOS1WriteADIOS1Read2D1x8/2x4/4x2 now runs in MPI.

Added GetVariableBase* in IO needed by C bindings and real-time
applications, nullptr is a valid state in return.

Added c bindings test under testing/adios2/bindings/c
Updating ReadMe.md to include ADIOS2_USE_C for C bindings

signed char needed by int8_t in C bindings
Added tests

Refactored IO, Variable class due to common functionality

Wrapper classes CompressBZip2 and CompressZfp implemented
Under transform/compress and adding examples and tests
Added/Modified cmake files
Makign changes to cmake from PR review

To do:
Add more tests

Copy constructor was implicitly removed for ADIOSPy due to m_ADIOS.

PyBind11 needed the copy constructor.

m_ADIOS is now a shared pointer to avoid copy constructor removal

Separated MPI nonMPI test as ctest failed for MPI

Removed ADIOS copy constructor explicitly, as it wasn't allowed by clang
compiler in testing/xml/TestXMLConfig.cpp

Using more portable preprocessor definitions to avoid warning on Windows
for ctime and fopen

Introduced std::throw_with_nested for bad_alloc in STLVector Capsule

Removed std:: in C function calls to avoid confusion with actual C++
only calls

Bugs: 1) Missing binary mode in FilePointer fopen and FStream ofstream
transports
      2) Replacing reinterpret_cast of size_t to uint_64, not the same
on Windows 64-bit

Removed some warnings generated by Visual Studio

Added static_cast for type conversions

Refactor XML reader to restore original check on single engine
conditions and eliminate warnings. Test added.

Allow ctime and fopen "not secure" warnings: now using binary fstream as
default file IO library on Windows

Using language primitives in test data instead of fixed width integers.
casting size_t to unsigned long in mpidummy to remove warning on Mac

Added test for generating profiling.json
Fixed inclusion for NLohmannJson json.hpp in Test
Tested resulting profiling.json on R (jsonlite), Python (json)
and C++ (json for modern C++)

Checking std::ios_base::failure exceptions
IOChrono is off by default, each owner turns it on explicitly
Modified FileDescriptor and FilePointer destructors
Added Tests BPWriteRead for stdio and fstream
Removed IO AddTransport with vector (shoud have been there?) to enable
AddTransport in Tests