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

Change: make GetPartialZ consistent, meaning Z of adjacent slopes continue

Previously, on a straight line of a one corner up slope with the adjacent
steep sloop the Z would increase one step every two sub pixels, except for one
case where one sub pixel is skipped. Similarly, a steep slope with two
adjacent one corner up slopes, would have a bump in the height line along the
diagonal whenever it enters/leaves the steep slope tile.

Codechange: pass "ground vehicle" to GetTileSlopeZ since for tunnel/bridges there are two states

Previously it checked the position in non-driving direction to "guess" whether
a ground vehicle was using the function, so on tunnels/bridges it could either
return the Z of the (virtual) ground compared to the Z of the path the vehicle
would take.

Fix #10362: NewGRF bridges without speed limits.

For bridges, a max speed of 0xFFFF (i.e. no effective limit)
is no longer displayed as a limit in the UI.

A max speed of 0 is also considered unlimited, for similarity to the
roadtype and railtype interface.

Fix #9869: remove docking tile when doing a clear square

Terraforming through objects placed on water didn't properly remove docking tiles as expected.

By moving some logic regarding removal of docking tiles into DoClearSquare, the issue is solved, while also simplifying code, avoiding repetition elsewhere.

Codechange: Template DoCommand to automagically reflect the parameters of the command proc.

When finished, this will allow each command handler to take individually
different parameters, obliviating the need for bit-packing.

Codechange: Let the compile generate the master command table out of templated command traits.

This is using a non-intrusive type-traits like templated system, which
allows compile-time validation that the command table and the command
enum match up.

Codechange: use "[[maybe_unused]]" instead of a wide variety of other ways we had

While at it, replace OTTD_ASSERT with WITH_ASSERT, as this
is always set if assert() is valid. No matter if NDEBUG is set
or not.

Fix #7656: destroying a tunnel/bridge now first removes the tracks for cost calculation

This means that for rail tunnel/bridges, the rail is first sold,
and the tunnel/bridge is destroyed after. This means destroying
tunnels/ bridges now often makes you money, instead of costing.

Similar, with road/tram tracks. Destroying a road+tram
tunnel/bridge now costs the same amount of money as first
removing the tram tracks and than destroying the road
tunnel/bridge. Especially as tram tracks generate money when
removing, this is a noticeable difference.

Fix: replacing a bridge didn't charge for clearing last tile

It only considered the end-tile (or start-tile) for the bridge,
instead of both. This is obvious in the rest of the code which
constantly does "+ 2"; this being the only place that does a "+ 1".

Fix: Use after free in CmdBuildTunnel (#6856)

Use after free could occur when when excavating far end
removed multiple NewGRF objects