add shape checks for read/write (disk vs. memory)

added shape checks and self tests for read and write -- check that shape of memory array and disk array match for read, and for write if variable exists. Return error code if they don't.

fail build if HDF5 broken and not a subproject

• harmonize layout with h5fortran
• fail if HDF5 is broken and h5fortran is the main project.

BUGFIX: reading into a slice of an array

fixed BUG: reading into an array slice failed due to bug in C-Fortran interface. This has been fixed by using a buffer variable inside h5fortran.

cmake: don't give fatal_error if hdf5 not found, let calling project decide that.

cmake BUGFIX for compiler flags, increase findHDF5 robustness

• CMake: fix bug in cmake_fortran_flags syntax
• increase robustness of FindHDF5, especially for HDF5 1.10.6
• don't build selftests when used via FetchContent

cmake: findHDF5 increased robustness

Find auxiliary libraries when HDF5 compiler wrapper is not working

cmake: backport findhdf5 for better finding

Anaconda / Miniconda has broken HDF5 wrapper that can trip up old CMake FindHDF5. So we made a CMake MR accepted for CMake 3.18, that is backported here as cmake/Modules/FindHDF5.cmake

dev / quality: cleanup build for better templating

cleanup build scripts for easier templating. Cleanup CI

modernize CMake

provide imported target h5fortran::h5fortran and associated package info as per modern CMake best practices.

easy io: h5write, h5read

For the simplest possible Fortran interface to HDF5, we added the h5save and h5read subroutines.
They are polymorphic scalar..7d, int32/64, real32/64

use h5fortran

call h5write('foo.h5', '/x', x)

call h5read('bar.h5', '/y', y)

try to close file if write fails, internal cleanup

for non-user facing interfaces, reduce excessive OO usage that is better handled as plain variables due to its ephemeral natures

tries to close datasets and files if an error occurs.