Fix: only count distance traveled in vehicles for cargo payment (#11283)

No longer you can utilize the free (and instant) labour of station
workers, transporting your cargo from one part of the station to
the other. No more!

Based on patch by dP.

Fix: don't compare next_station when trying to merge CargoPackets

For vehicle packets they shouldn't be compared, and for station
packets they are already in a bucket per next_station.

Fix b0e73277: cargodist information got lost when splitting of cargo (#11280)

During b0e73277 we removed loaded_at_xy, but I kinda forgot that
it was a union with next_station. Now next_station wasn't copied
anymore, or checked in AreMergable.

Codechange: cleanup CargoPacket in terms of variable/function names (#11278)

Over the years, things got reused and changed, making the current
names somewhat unclear in what they actually mean and do.

Codechange: Reorder some high-use structs to reduce their size. (#11201)

This reduces GoodsEntry from 144 to 136 bytes (thereby reducing Station from 9704 bytes to 9192 bytes), and CargoPacket from 40 bytes to 32 bytes.

Codechange: simplify the type of loaded_at_xy / next_station (#11182)

It was TileOrStationID, most likely to make sure both types in
the union are identical. But as TileIndex is a StrongTypeDef
that becomes a bit weird. So instead, still make sure they are
of equal size, but define their individual types better.

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: Make SpriteType, CargoSortType, SourceType and ScriptType enum classes. (#10663)

This avoids a (soft) namespace conflict between the four ST_* enums.

Change: Increase max cargo age and let min cargo payment approach zero. (#10596)

Co-authored-by: Michael Lutz <michi@icosahedron.de>

Codechange: remove the special station/vehicle code from SaveLoad

With the new SLEG_STRUCT it is much easier to embed a struct
in a struct, where the sub-struct has limitations on when it is
being used.
This makes both the code easier to read (less magic) and avoids
the SaveLoad needing to know all these things about Stations
and Vehicles.

Codechange: C++-ify lists for SaveLoad (#9323)

Basically, this changes "SaveLoad *" to either:
1) "SaveLoadTable" if a list of SaveLoads was meant
2) "SaveLoad &" if a single entry was meant

As added bonus, this removes SL_END / SLE_END / SLEG_END. This
also adds core/span.hpp, a "std::span"-lite.

(svn r17113) -Change [FS#265][FS#2094][FS#2589]: apply the subsidy when subsidy's destination is in station's catchment area and cargo packets originate from subsidy's source
-Change [FS#1134]: subsidies aren't bound to stations after awarding anymore, they still apply to town or industry, no matter what station is used for loading and unloading. Awarded subsidies from older savegames are lost
-Change [NoAI]: due to these changes, AISubsidy::GetSource and AISubsidy::GetDestination now return STATION_INVALID for awarded subsidies

(svn r16694) -Fix [FS#2995] (rgradual loading, rnewindustries): only pay for whatever has been actually unloaded and perform the payment when unloading has finished. This fixes, amongst others:
* cheating by starting to unload and after getting paid rushing to the depot to get sold (or unloading, loading and getting paid again for the remainder)
* cargo being dropped onto a station at the moment a stockpiling industry doesn't accept it anymore
* industries getting cargo that has not been unloaded yet and subsequently dumping it back on the station in one go
Note: you will now get paid after the unloading has finished, so you'll have to wait a bit longer for 'your' money.

(svn r16338) -Codechange: split loading of references to two phases
In the first phase, indexes are stored. In the second phase, indexes are checked for validity and converted to pointers