hdf5_ep

Merging in latest from upstream (HDFFV/hdf5:refs/heads/hdf5_1_10)

* commit 'b20ffd84e3572cd506bf1f696431892258e9ab3b':
  Updated the command for external_env and vds_env to the most recent changes.
  1. Updated the commands for compiling two new tests (external_env.c and vds_env.c). 2. Changed the data file names for external.c and external_env.c to avoid potential name conflict.
  HDFFV-10658: setting and getting properties in API context.  Porting the changes to the develop branch into the 1.10 branch: mainly the external file prefix and VDS prefix.