Fix #10452: Don't let AyStar max_search_nodes unattended when initializing (#11544)

Add a constant with the default value of 10000 and have the pathfinding settings refer to it.

Add a preventative method to AyStar when it's initializing, to limit the number of max_search_nodes if left unattended.

Codechange: automatic adding of _t to (u)int types, and WChar to char32_t

for i in `find src -type f|grep -v 3rdparty/fmt|grep -v 3rdparty/catch2|grep -v 3rdparty/opengl|grep -v stdafx.h`; do sed 's/uint16& /uint16 \&/g;s/int8\([ >*),;[]\)/int8_t\1/g;s/int16\([ >*),;[]\)/int16_t\1/g;s/int32\([ >*),;[]\)/int32_t\1/g;s/int64\([ >*),;[]\)/int64_t\1/g;s/ uint32(/ uint32_t(/g;s/_uint8_t/_uint8/;s/Uint8_t/Uint8/;s/ft_int64_t/ft_int64/g;s/uint64$/uint64_t/;s/WChar/char32_t/g;s/char32_t char32_t/char32_t WChar/' -i $i; done

Codechange: split settings.ini over several files (#9421)

This reduced the load on compilers, as currently for example MacOS
doesn't like the huge settings-tables.

Additionally, nobody can find settings, as the list is massive and
unordered. By splitting it, it becomes a little bit more sensible.