This means the shared memory struct is just 255 bytes longer than a few
commits ago instead of 32K.
Also introduce a function for putting path strings in the shared memory
as there was too much copied and pasted code and it was error-prone.
Also free some handles once we're done with them so they don't leak.
Well... unless we fail to get the user profile directory.
Also put freeze dumps in a more appropriately-named file.
Discussed in https://gitlab.com/OpenMW/openmw/-/issues/7455
Manual rewrite of c21695c951
As well as that, I found a bug where the crash dump path was being converted from a std::filesystem::path to a utf8-encoded std::string, then passed to the crash catcher, which converted it to a std::filesystem::path implicitly, but using the system eight-bit code page, which wouldn't usually be UTF-8. That's now fixed by passing the function that expects a path a path instead of a string.
