Dropped support for ubuntu 20.04

Fix h5pp::format and h5pp::print for fmt versions < 8

Ignore .vs

Patch FindFilesystem.cmake that was failing in v1.11.0

Updated quickstart example

Updated cache action

Reintroduced patch to automated HDF5 to export zlib and szip as publi…

…c dependencies

Reduce minimum required cmake version to 3.15

Use NEW policy CMP0074 to let find_dependency use _ROOT variables

Updated bundled FindHDF5.cmake to support CMake 3.19+

* replaced target hdf5::hdf5 with hdf5::all to avoid conflicts with new target naming convention
* The old target name hdf5::hdf5 is now defined by official FindHDF5.cmake as the target for the HDF5 C library "libhdf5"