Add an option to choose the name for the memfd

[notmarek]

this should be useful to hide from apps that scan the maps file for unexpected memfd's by choosing something like jit-zygote-cache (this is useless with --hide)

[MJx0]

Hi, thanks for contribution.

Since you added memfd_name to inject_elf_config_t struct then you can access it via _cfg.
you don't need to add a function parameter for it, you can simplify it by changing one line:

std::string memfd_rand = !_cfg.memfd_name.empty() ? _cfg.memfd_name : KittyUtils::String::random(KittyUtils::randInt(5, 12));

I haven't tested this but if memfd name like "jit-zygote-cache" already exists then there will be multiple entries so will findElf and findSoInfo return the correct one?