Fix memory overwriting by EnumToString & StringToEnum

[FileEX]

Fixes #4078

Based on PR #4085, it was determined that the strange memory overwriting errors after using EnumToString / StringToEnum are a result of passing a type smaller than 4 bytes, causing the remaining memory to be overwritten (thanks @Merlin for solving this puzzle, although it's simple, I didn't think of it for a moment why the memory was magically overwritten).

The solution is to get rid of casting to a 4-byte size and dynamically determine the type and its size. Tested on several different variants, and I haven't detected any additional issues related to this PR.

I had to modify several enums because now a given value in ADD_ENUM must be associated with the enum provided in IMPLEMENT_ENUM_BEGIN and must be of the same type due to templating. I leave IMPLEMENT_ENUM_CLASS, etc., for compatibility (too many places in the code use it, so I didn't want to change it to IMPLEMENT_ENUM now).

Advanced template methods and complex (hard-to-read) macros are not my strong suit, and I don't claim that this solution is the best possible, but I tried to change as little as possible and maintain compatibility with the current code, and most importantly, as I mentioned – it works, and I haven't noticed any issues.

[Dutchman101]

Thanks for the digging and collaboration (@ others), due to release schedule and desired features this was requested and therefore it'll have an expedited merge. After all it was thoroughly researched, too.

It will get further testing in a nightly