Codechange: refactor DecodeHexText to a generic purpose ConvertHexToBytes (#11866)

DecodeHexText() does more than just decoding hex. ConvertHexToBytes()
now only does pure hex decoding. This required a bit of refactoring
for the code using DecodeHexText().

Fix #11644: Off by one error/buffer over-read in StrMakeValid (#11645)

* Fix #11644: Off by one error in StrMakeValid UTF-8 decode overrun detection

* Fix #11644: Off by one error in StrMakeValid buffer last character

* Fix: Unnecessary string duplication at StrMakeValid call sites

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

Cleanup: remove str_strip_colours; StrMakeValid also removes the colours

Essentially str_strip_colours followed by StrMakeValid makes the calling of
str_strip_colours useless, as StrMakeValid would have removed them too.

Change: [Network] Transfer command data as serialized byte stream without fixed structure.

The data will be transmitted as the length followed by the serialized data. This allows the command
data to be different for every command type in the future.

Codechange: move casting a "const char *" to "char *" to the caller

It is not nice to have your definition say you won't change a value
while in fact the whole reason for your existance is to change it.

Codechange: rename str_validate to StrMakeValid(InPlace) (#9304)

This to be more explicit the function changes the value, and not
returns yes/no.

Fix: String validation could leave invalid Utf8 encoded strings (#9096)

In case a character was encoded in multiple bytes, but required fewer bytes to be encoded, the first byte would be copied to the output leaving an invalid Utf8 encoded string. Later uses of the validated string would use the same decode logic, which would yield a question mark and just read a single byte, so nothing dangerous happened.
Furthermore, because the next byte would not be a first byte of an encoded Utf8 character, the last few valid characters could be removed by the validation as well.

Fix: unbreak building with ICU on macOS

A symbol clash breaks building ICU on macOS, and although it isn't
necessary, it might as well be possible.

Codechange: ICU_SORT is in reality ICU_I18N (according to their CMake files)

By naming it in a different way, things get a bit confusing.
Especially if we are switching to CMake, which autodetects these
things, we need to use the name the authors of ICU gave it; not
our interpertation of that name.

Change: [Win32] Use Uniscribe instead of ICU for text caret handling.

This removes the need for the ICU lib on Windows.