Cleanup: Remove some unused functions. (#11429)

These were picked up with cppcheck.

Codechange: Allow using more than 65536 NewGRF string IDs.

NewGRF string allocation allowed up to 524288 strings, however stringid was passed as uint16_t which limits to 2^16.

Change: Replace fixed length _grf_text array with vector.

Additionally reshuffle GRFTextEntry for better alignment.

This removes a mostly-unused static 20MB allocation.

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

Remove: obsolete NewGRF text unprinting. (#10884)

Co-authored-by: Rubidium <rubidium@openttd.org>

Fix: fmt's {:#04X} yields '0X00', not '0x0000'

Technically the 0X vs 0x is not a big problem, just not pretty. However, the
length also including the 0x results in unexpected behaviour, so it probably
better to not use it.

Fix 11ab3c4: [NewGRF] Overflow when determining cargo mask for string code 9A 1E

9A 1E: Print unsigned word as name of a cargo type (translated for GRF version >= 7).

Codechange: Replace SmallPair with std::pair.

std::pair is already the smallest possible pair, and it already handles non-POD types correctly.