Renamed all HDF5 examples build options from H5EX_* to H5EXAMPLE_* to better distinguish them from library options when building examples alongside the library.
Updated all CMake files, including:
Main examples CMakeLists.txt files
CMake configuration files in config/ directory
CMake preset files
Updated documentation files to reflect new option names
* Cleanup threads package checks
* Check first if package was found
* Remove unnecessary dependent checks
* Remove Unused options and fix names of option prefix
* Merge examples repo into library
* Change grepTest to be more fault-tolerant
* Update examples macro file
* Exclude all Fortran examples from doxygen