Introduces zstd support switch

[PALoizeau]

• Check with a CMake compile-link test if boost::iostream provides the zstd filtering
• Enable ZSTD (un)compression only if it is the case, using some preprocessor variable set from CMake

This scheme could probably be also used for other compression filters such as LZMA, allowing to tune allowed filters depending on what is available on current node

This is the patch proposed in https://git.cbm.gsi.de/j.decuveland/cbmroot/-/merge_requests/2, but applied directly to Flesnet

• Follow-up of #132
• Part of user-feedback from CBM-TOF to #116

[cuveland]

Works and looks fine to me. Thanks very much!