* Implement support for loading of Virtual File Drivers as plugins
Fix plugin caching for VOL connector and VFD plugins
Fix plugin iteration to skip paths that can't be opened
* Enable dynamic loading of VFDs with HDF5_DRIVER environment variable
* Temporarily disable error reporting during H5F_open double file open
* Default to using HDstat in h5_get_file_size for unknown VFDs
* Use macros for some environment variables that HDF5 interprets
* Update "null" and "ctl testing" VFDs
* OESS-98 convert plugin option to FetchContent, add tests
* Fixes for pkcfg files because of plugin option
* OESS-98 fix tools test for plugins
* Keep doxygen comments under 100 chars long - format hint
* Whitespace
* HDFFV-11144 - Reclassify CMake messages
* HDFFV-11099/11100 added help text
Modify h5repack to integrate with VOL connectors
Update tools library to accomodate VOL connectors
Update logic in h5tools_fopen for VOL connectors
Add command-line options to h5repack for specifying in/out VOL
connectors
Implement h5tools_set_vol_fapl
Fix library shutdown issue
Integrate ROS3 and HDFS VFDs into new h5tools_get_fapl() scheme
Avoid H5Ocopy in h5repack when using different VOL connectors
Update h5tools_test_utils.c for ROS3 and HDFS integration
(2) Add two new options to h5repack for low and high bounds as in H5Pset_libver_bounds.
(3) Modify message pre_copy callbacks so that H5Ocopy can handle version bounds check.
(4) Add version bounds check for cache image feature.
