Feature: [NewGRF] Related Act2 objects for airports and airport tiles.

Airports are similar two stations and industries, both of which have the town as related object.
Airport tiles are similar to industry tiles, which have the industry as related object.
This seems a sensible structure, so let's make it Airport Tile -> Airport -> Town.

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: Add missing `this->` in override manager.

Variable scope is also tweaked in a couple of cases reducing line count.

Feature: NewGRF callback profiling (#7868)

Adds a console command newgrf_profile to collect some profiling data about NewGRF action 2 callbacks and produce a CSV file.