Add simple fuzzer (and fix various memory problems) to be able to integrate libcacard in oss-fuzz
Per [1], we are good to go to integrate in oss-fuzz. This adds a simple fuzzer and some housekeeping/preparatory work around build system to be able to build fuzzers for oss-fuzz.
I am not an expert in Meson so I would be glad for feedback if things can be done more meson-way or simpler than I did that. But still it looks ages nicer than my autotools attempts.
After this will be in and it will work in the oss-fuzz, I would like to create some corpus for fuzzer to have something to start with.
Update: The PR for oss-fuzz [2] with this branch looks good now, but I would like to get this reviewed and merged before the oss-fuzz PR.
Update 2: The oss-fuzz PR [2] is already merged and fuzzing from my branch. Once this will be in, I will update the oss-fuzz to point to current master.